For artists, it's another story. The dirty little secret of services like Spotify and others is that they are not particularly lucrative for artists. At all. Each of them has managed to court record labels with attractive enough licensing deals, but that doesn't necessarily trickle down to the artists themselves. As a result, many artists have held back new releases from streaming services, or jumped ship all together.

Initially, independent artists such as bands on small metal labels started to question the value of Spotify and pulled their catalogs. Then bigger artists like The Black Keys and Coldplay declined to release new material on Spotify.

Exact figures range (and are seldom made public), but it's clear that streaming services simply do not pay out much money compared to physical album sales or paid downloads. According to CDBaby, iTunes accounts for 77.4% of digital revenue for indie artists, while sources like Spotify and Rhapsoy bring in about 2% apiece. Now, with iTunes Match, artists get an additional stream of revenue on top of their initial digital album sales.

In theory, the streaming services will grow their user bases and refine their monetization strategies to a point at which things are fair for labels, fans and artists alike. In the meantime, not everybody is willing to stick around and wait for their business model to mature.

More than 3 million people are now paying to use Spotify, according to the Financial Times. That's a conversion rate of more than 20%, a figure that has reportedly increased by 5% since the service hit 1 million users last year. In other words, not only is Spotify itself growing, but the rate at which people sign up for a premium or unlimited account is also increasing.

It also doesn't hurt that the six-month window of unlimited, free streaming music for new users has begun coming to a close for the service's earliest U.S. adopters. As that happens, those who are truly hooked on the service are forced to either put up with listening caps or cough up $5 per month to remove them. The company hasn't said what percentage of those paid users have opted for the pricier "Premium" account, which allows for mobile streaming in addition to stripping out ads and listening caps.

This isn't to say that there aren't still major, outstanding questions about Spotify and the viability of the all-you-can-stream model it shares with the likes of Rdio and MOG. The music labels are evidently happy enough with the arrangement to stay on board for now, but the artists are a different story.

The streaming services pay out notoriously low royalty fees to artists, some of which have begun to question the value in being on the service. Sure, it's a great way to promote one's music, but it may not be economically advantageous for artists, especially if it ends up hurting record sales.

Digital music only continues to grow and mature, as streaming services explode, Internet radio companies go public and developers begin using the power of open APIs to mash up sounds and services. SoundCloud alone saw 231% growth last year, while Twitter saw a 104% increase in music-related activity.

What's interesting, though, is how the Web is paving the way for unsigned, independent artists to reach levels of popularity that rival major label acts. This is especially true on SoundCloud, where unsigned artists flock to upload their recordings. But even across the larger Web, three unsigned artists broke into Next Big Sound's "Social 50" list, which chronicles, the 50 biggest artists across all of the social and music sites that they track.

These numbers, while impressive, should be taken with a grain of salt. Next Big Sound has gone to great lengths to pull data from sources like YouTube, Rdio, Last.fm, Pandora, SoundCloud and several others. One service missing from their list is Spotify, which just launched in the U.S. this past summer and has seen enormous growth since then. Still, it looks like they're using a pretty hefty sample of online music data to draw their conclusions. You can take a closer look at their methodology. if you're curious.

Music streaming service Pandora, for one, is staying out of Facebook's social apps completely. "It's true that music is a social experience, but it's also a very private experience," Pandora founder Tim Westergren recently told CNN. "We have to be very cautious."

Some of the new social apps include food-photo app Foodspotting, recipe app Foodily, ticket-buying app Ticketmaster, the visually oriented social network Pinterest, movie-reviewing site Rotten Tomatoes, and travel site TripAdvisor.

The open graph push officially happened on Wednesday, but news made its way around the tech news world on Tuesday.

At f8 last year, Zuckerberg laid out the future of social apps: "We think that people are going to want to share all kinds of things with their lives and we think that apps are the way they want to show them."

Because, believes Zuckerberg, "no activity is too big or small to share."

Not everyone agrees. Not all information is public, and it's up to the user to decide what they feel comfortable "sharing," opting-out if necessary. Our own John Paul Titlow turned off his Facebook Spotify integration months ago.

Listening to music alone, either on a jog or just laying in bed, is one of those meditative experiences. So is reading articles that are longer than 500 words. Instapaper is one avenue for that long-form reading experience. Users can, of course, share the stories they've instapaper'ed out to Facebook and Twitter. But would Instapaper ever consider a Facebook social app?

"I don't believe that people want to auto-share everything they read without some other manual filter in front of it," replies Instapaper founder Marco Arment.

Spotify's free accounts are normally restricted to ten listening hours per month. If you really, truly love a particular song, you'll only be able to stream it five times in a given month. These caps will come on top of the usual limitations of free accounts: You have to listen to advertisements and there's no mobile access.

The question of whether users will convert to paying customers is crucial to the viability of Spotify's business model. The company has deals in place with all of the major music labels and many independent ones, but those relationships are not necessarily set in stone, nor did they come about easily. Its U.S. launch was delayed due to extended negotiations with the labels. More recently, concerns have been raised over the relatively small payout seen by artists, a few of which have opted to keep their new releases off of Spotify.

For this year's ReadWriteWeb list of the most important and influential consumer-grade cloud computing apps of the year 2011, we focused our gaze on services that truly fit the formal definition: specifically, services that 1) utilize a remote resource of 2) variable capacity 3) which the user can provision for herself, 4) which is mostly or totally independent of programs installed on the user's devices or PCs, and 5) which is not just a Web site with a big server. You may have seen Facebook on some publications' Top Cloud lists already; by our definition, Facebook is not a cloud service. But we did look for providers that perform innovative, discrete functions built around their services.

Hosting services are not cloud apps for purposes of this list; and there are plenty of innovative hosts to consider (we gave serious thought to Wistia), but in the end we decided that a hosting service is not really an application unless it provides a discrete function that goes over and above simple storage or sharing. Analytics, which Wistia provides, is right on the edge, but it's really a measurement of a byproduct of using the service as opposed to a function that users actually perform. That's not saying Wistia isn't a great idea; it just belongs on another list.

10. CloudApp. The largest single category of cloud apps for consumers is storage and retrieval, which is understandable because it's a service that everyone needs to one degree or another. What's interesting is how certain services innovate on this theme, and especially whether they give themselves room to continue innovating.

CloudApp is for Mac OS and iOS users at the moment, and its innovation is that it's building a little ecosystem around itself. It utilizes your choice of quick-and-easy gestures for designating a file or object to send to CloudApp's storage, the most basic of which is dragging and dropping the object to CloudApp's icon in the taskbar. In exchange for this gesture, CloudApp produces a URI which is copied to the Clipboard. From there, you can paste it into an e-mail, a tweet, or an IM message; when your recipient receives the link, she has instant access to the object.

The way CloudApp innovates is by incrementally enhancing what can be easily uploaded, and how those objects can be utilized in their native context. One example is screenshots: You can designate a key for taking a screenshot and uploading it in one fell swoop; the recipient sees your link, clicks on it, and sees your screen. There's no exporting or importing necessary here.

But what hoisted CloudApp onto our Top 10 list this year is how well the company is promoting Raindrops. This is an extremely clever, self-promotional idea for enabling developers to build their own tools that utilize CloudApp in similarly contextual ways, with the help of CloudApp's own API. One example the company created at the time this feature was launched in April 2010 is for Adobe Photoshop; since then, the community has contributed a truckload more, including an intelligent link interpreter for Twitter and a stand-alone CloudApp client for iOS called Stratus.

Here's an example (above) of another add-on you can't even see (which is a good thing): The maker of SparrowMail used CloudApp's API to develop a way to do simple drag-and-drop of attachments into e-mail messages, bypassing Mac OS' sometimes convoluted series of steps.

Building a community around something as simple as an app is a difficult thing for a small company to achieve, especially when it's in competition with a plethora of other vendors in the same category. CloudApp is pulling this off brilliantly. (It's worth noting that the service is built on the open-source Heroku platform from Salesforce, thus answering RWW's question from last year on whether developers will trust Heroku: Yes.)

9. Waze. What would be nice is if someone hired a few thousand cars to drive around each town looking for traffic incidents, and report on them in real-time. Let's see, $25 bucks per hour salary times 1,000 reporters times 50 cities... I'll get back to you on that idea.

Or, what would be brilliant is if someone leveraged the platform that's already in existence to enable a few thousand folks to do this job passively and voluntarily. Waze is a system that utilizes the GPS information being pinged back from iPhone, Android, Windows Mobile, and Symbian devices. It's been in existence since 2006, but last October the 3.0 version of the service introduced a fabulous new feature (so far, just for the iPhone users) that integrates with Twitter. This way, people can tweet on what's happening in their neighborhoods (including the good things, like street fairs) from right where they're standing.

Okay, maybe there aren't a thousand Waze users in a city like mine (Indianapolis) just yet, but it's surprising what you can find. There's updates on traffic accidents and reported police sightings (which are rarer in some cities than others). What Waze demonstrates is that there are ways of making use of data that can be collected passively from a crowd of users, in ways that do not jeopardize privacy.

8. Box.net. This is one of the services that comes to most folks mind when they know what a cloud app is. What's kept Box.net in the news, including just this month - and what keeps Box.net on our list this year - is a constant stream of innovations. Customizable synchronization is one example from last fall; and earlier this month, a completely revamped iOS app that enables features like uploading photos and videos to discrete folders. This puts Box.net on a par with dedicated photo-sharing services that simply can't expand its features list to Box.net's size. And just this morning, the company launched an enterprise-grade option for unlimited storage.

Next: Playing your own tune...

7. Audiobox.fm. My wife and I are both Pandora fans, although last year I found it ironic that both of us had been working - albeit without admitting it to ourselves - to make Pandora play music we actually already owned. Yes, that sounds like a pathetic waste of precious seconds, but there it is.

Audiobox.fm, launched last year, is the streaming service that folks need anyway: one which enables them to store the music they own in the cloud ($3.99 for 11 GB is pretty fair) and also play that music from any device using the service's own media player. ITunes users who were a bit discouraged last year by Audiobox.fm's dedicated player were treated this year to the option of streaming their own M3U files from cloud storage, to their player of choice (with variable results, especially in the case of Winamp, but not for lack of trying).

6. Joukuu. We introduced you to this storage maintenance service last month, calling it a "cloud cloud." It's a Web-based console for displaying in a single list the contents of files stored to Google Docs, Box.net, and Dropbox (Microsoft SkyDrive support still forthcoming). When you work with many colleagues on a project, and they all subscribe to different services (often the case with independent contractors who happen to be paired together), Joukuu is a true timesaver. And the drag-and-drop functionality of its outside-the-browser app saves you about a thousand clicks per day.

5. Hojoki. (If you weren't looking carefully enough, with definitions of Joukuu and Hojoki, you'd think this would be a foreign language course.) Entire billion-dollar-plus industries are built around so-called "collaboration platforms" that enable sharing and versioning of documents among members of teams. And yet there are individual cloud apps (Beanstalk, Dropbox, Evernote, GitHub) that are involved with the individual tasks around collaboration, and which all have managed identity, but which are not linked together.

So it really took more clever observation than creative genius to create Hojoki, but the premise works just the same as if genius were involved from the beginning. Hojoki is a messaging system that looks an awful lot like something you'd see from Salesforce. It builds a stream of people with whom you're already sharing contacts, and lets you organize them into groups for collaborative projects. The activities that all of you share within that group are pipelined through the Hojoki stream to everyone in that group, so it becomes an automatic task progress monitor. The service is currently in beta, although it's already made significant inroads, and there will be a business model attached to a premium service once the beta cycle is complete.

4. Do.com. Nothing more thoroughly demonstrates the rapidly changing state of the applications market in general than the fact that Microsoft Outlook's greatest competition in over a decade comes from something that isn't really an e-mail client. Do.com from Salesforce includes the level and ease of functionality for file sharing and collaboration that enterprises may have already attached to Outlook by way of add-ons, but which aren't available for everyday Outlook users.

And by tying Do.com to Gmail as its primary messaging service, Salesforce is wedging itself beneath Outlook and threatening to uproot it from home users' and small business users' systems. Do.com may not be a threat yet to Exchange, though it may put a dent in Hosted Exchange services for smaller businesses. Nonetheless, it's demonstrating that even an e-mail client with "2010" in its name is looking more and more like "1980."

Next: Is there beauty yet to be found in the cloud...

3. Spotify. The reason for the decline, if not yet outright collapse, of the global recording industry is that it is has not been meaningful or desirable for consumers to own music. The industry's principal delivery system for music, even to this date, remains a container that consumers no longer want; and the system that consumers prefer, and which a majority of them now actually use, is something that the industry has yet to truly embrace. Services like Last.fm and Pandora are more convenient than music ownership and, for more users today, more interesting than radio.

Spotify gambles with the notion that $9.99/month subscriptions to its premium mobile services (estimated last month at about 2.5 million) will be enough to pay down the royalties it undoubtedly owes for all its users, including those who use the free Spotify Radio desktop app to choose the music they want from Spotify's huge library. RWW's John Paul Titlow has been covering Spotify and Spotify Radio very thoroughly, in part 1 and part 2; and RWW's Jon Mitchell named Spotify #6 in his list of overall Top 10 Consumer Web Apps for 2011.

But what made Spotify qualify here again as a Top Cloud App is something it didn't have last year: an apps ecosystem of its very own. If you're thinking we've screwed up and posted a picture of Last.fm instead... well, it's no screw-up. Spotify's new desktop application, with music recommendation apps built-in, is so strong that it includes Last.fm as one of its recommendation providers, along with Rolling Stone magazine and TuneWiki.

When fully built out, the Spotify apps ecosystem will enable what the company is calling an "authentication layer" between record labels, app developers, and users. The technology that the record industry could not find it within itself to build for itself, may just end up being built for it. When that happens, it may have a certain deity to thank, followed immediately by Spotify.

2. iCloud. The establishment of Apple's stronghold in devices, and the services that support them, was deliberate, systematic, and in almost every aspect of its execution, brilliant. The exception was MobileMe, a service whose frequent slip-ups and uncharacteristically dramatic failures led Steve Jobs to openly declare its launch "not our finest hour."

Therefore iCloud could be noteworthy for having (at least thus far) not been a spectacular failure. But the brilliance of Apple's marketing has left many with the impression that iCloud has no direct competition with Android. What Android does lack, and what iCloud does provide, is a context of the service as an ever-present resource that's attached, albeit ethereally, to the iPhone, iPad, and Mac. Of course it's an Apple-only service, but haven't all Apple-produced disk drives since 1978 been Apple-only? From Apple's perspective, why must a virtual device, by definition, be more platform-agnostic than a physical one?

Because it's just another Apple device, it's programmable like an Apple device. Developers can build apps around it, and create new functions and methods that Apple Corp. hasn't even foreseen. For any other platform, this would be a great thing; from Apple's perspective, it could easily become perceived as an effort by independents to trim their way through Apple's carefully walled garden. Expect some "openness" issues to crop up around iCloud throughout 2012.

1. Evernote. Bill Gates was known to have overused the word "great" during his press appearances as the head of Microsoft, so there are probably thousands of sound bites of the phrase "great apps" just waiting to be compiled into the next great, annoying YouTube mash-up. Only a few apps get to be described as things of beauty.

At its core, Evernote does one thing, and does that very well. It collects clips of data from the Web sites you're reading or the applications you're using, and gathers them into categories that can be synced in the cloud and accessed from multiple devices. I noticed Evernote had pervaded the apps repertoires of many of the Syracuse University students we covered during last month's MLB.com Apps Challenge. Now that laptops, tablets, and in some universities, thin client desktops are the principal research tool of every scholar, Evernote has quickly risen to the level of ubiquitousness among this specific class of users - as invaluable to the work they do as Twitter.

Whether Evernote rises to the level of "beauty" depends on whether it raises its batting average of late. My friend and colleague Joe Brockmeier discovered the latest app in the Evernote ecosystem, called Hello, was perhaps a little less than half-baked. Nevertheless, the core of Evernote has joined Box.net, Dropbox, and Google Docs as the very definition of "cloud app" among users who know the cloud, and who truly do get it.

When it comes to choosing which option to go for, the most you can do is take each service for a spin, run a couple searches for stuff you like and see what comes up. You can get a general feeling of which one's a better fit and go with your gut, but wouldn't some hard data be nice?

The results show Rdio coming out on top by a number of measures, despite the fact that Spotify is known to have a bigger selection overall. Several respected artists were only availble on Rdio, including Bob Dylan, Pink Floyd, Queen and Thelonius Monk. Both services have a ton of exclusive albums, but only Rdio can boast Pink Floyd's Dark Side of the Moon or London Calling by The Clash.

Spotify (at 4.8%) had slightly fewer exclusive albums than Rdio, on which 6.8% of the albums were available exclusively. Nine of the 100 most popular albums were only on Rdio, while only one of them was exclusive to Spotify.

To be fair, Rate Your Music is probably not the most authoritative source of what's popular. A more complex analysis might mash together datasets from Billboard, Last.fm and, if possible, Amazon user reviews to come up with a more comprehensive list of popular albums.

Not included in the study were services like Grooveshark and MOG, the latter of which does not make an API available to developers.

In the case of Spotify's new Web radio feature, we're not going to go so far as to say that it's a "Pandora killer," but its inclusion in Spotify's desktop client is going to give the up-and-coming streaming service a tangible advantage over the 11-year-old Web radio service.

The recommendations offered up by Spotify Radio are not quite as good as those on Last.fm or Pandora in many cases, but they're pretty solid and the feature has serious potential. We started stations based on a handful of artists across genres and time periods and found the results to be mostly appropriate without being too broad or overly obvious. We even tried a handful lesser known artists from a few decades ago and Spotify was able to rattle off sonically similar tracks.

The feature definitely has its limitations. For one, that stations based on an individual songs (rather than artists) seem limited. Those channels appear to operate as though you'd selected the artist, not the song. By contrast, when you put a specific track into Pandora, it looks for songs with similar aural qualities regardless of genre, time period or other broad characteristics. It does a pretty effective job of pairing up songs that actually sound similar. And if you don't agree, you can always hit the thumbs down button.

The experience certainly varies depending on what you enter. While many stations returned appropriate-sounding results, a station for the band Nirvana mostly brought up other well-known rock songs from the same era, including a slow, cheesy ballad by Aerosmith.

Spotify hasn't divulged what's fueling their recommendations, but it does feel pretty similar to results from The Echo Nest, which powers a number of music apps, including Clear Channel's Pandora cline, iHeartRadio. UPDATE: It is indeed the Echo Nest that's powering Spotify Radio, both companies have confirmed. The recommendation engine has some growing to do before it's a thoroughly viable alternative to Pandora. Still, the mere addition of such a feature to Spotify will make many users that much less prone to load up Pandora.

Spotify Radio is just the latest way users of the streaming service can discover new music. The company recently unveiled a platform for third party apps, included editorially curated selections from Pitchfork and Rolling Stone, as well as more automated recommendations from Last.fm. The app platform and the new radio feature will both be rolled out shortly to desktop users, but you can download a preview here.

The new features are not yet included in the Spotify desktop client, but curious users can download a preview of the next version of the software. We did and after using it, we're finding that the inclusion of third party apps makes Spotify much better.

Of the dozen or so apps that launched with Spotify's new platform, many of them are geared toward discovering new music, whether via human tastemakers or by algorithm. Reputable music publications like Rolling Stone and Pitchfork have apps, which further bridges the gap between the reading published reviews and actually hearing music.

Critic-curated Playlists from Top Publications

Pitchfork's app takes the experience of reading reviews and best-of lists from the influential publication and bakes that directly into Spotify itself, enabling immediate playback of the albums you're reading about. The app opens up to Pitchfork's "Best New Albums" list, from which any of the albums can be streamed (assuming they're available on Spotify, which most are). From there, you can browse the rest of their audio-enhanced reviews and view their repository of Spotify playlists, which include many the site's best-of roundups like the Top 500 tracks of the 2000s and the Top 50 Singles of 2003. Throughout the experience, almost every song you see listed can be heard and albums and lists can be added as a Spotify playlist for later listening.

The Rolling Stone Recommends app is a pretty similar concept, just from a more mainstream editorial perspective. All of the magazine's recent top-rated albums and songs can be streamed and the app offers playlists that tie in with recent features in Rolling Stone, such as the top guitarists of all time. The Guardian offers an app of its own, again based on the music its critics have recently reviewed.

Songs Recommended Based on Your Listening History or Mood

Professional critics aren't the only source of music recommendations on the new platform. The desktop client is now deeply integrated with Last.fm, a service that has long provided recommendations based on one's listening history. It can track every song you listen to in iTunes, Spotify and a variety of other services and devices and then serve up music based on what you're most likely to be into.

Rather than just letting you "scrobble" songs off to some other island called Last.fm, Spotify brings much of the Last.fm Web app's functionality directly into its desktop client. The "Overview" tab displays your vital stats: most listened-to albums, recommended music, loved tracks and recently scrobbled tracks. The "Now Playing" tab focuses on the music currently being played, whether it came from the Last.fm app or elsewhere, and give instant access to similar artists.

The "Recommendations" tab drills shows an expanded view of what's recommended on the app's home screen. This is where most of the magic happens. Each recommended album can be streamed instantly or added as a playlist within Spotify. As it's always done, Last.fm identifies exactly why it's recommending each album. Sometimes it's because you've listened to several similar artists, or perhaps you've already heard one release by that artist and want to hear more.

The functionality itself is nothing new. This is what Last.fm has done for years. But now that it's baked right into Spotify, it enables you to stream every recommended song or album in its entirety, all from a single interface.

If you're already a Last.fm user, the addition of this app alone blows the old Spotify experience out of the water. The integration breathes new life into Last.fm while making Spotify a much more useful service.

Another service that's available as an integrated app is Moodagent, a service that recommends music based on very specific musical qualities such as tempo and mood. It allows Spotify users to choose any song that happens to suit their mood at the moment, and then automatically build out a lengthy playlist of songs that are likely to evoke the same emotional response.

This is Just the Beginning

Other apps that are launching with the new Spotify platform include one for music aggregation site We Are Hunted, social listening service SoundDrop and Billboard. Songkick shows upcoming concerts by artist you've listened to, while TuneWiki displays lyrics in time with when they're sung during a song.

As much value as these apps add to the experience of using Spotify, it's really just a handful of partners the Swedish service has opted to launch with. This is really just the beginning. The platform is now open to developers, who can use the same HTML5 and JavaScript they're accustomed to using to build Web apps. Spotify is requiring apps go through an Apple-style approval process, but hopefully it won't be unreasonably rigorous and will help to keep the directory clean of useless apps and malware.

Developers are wasting no time getting started. Andy Smith, creator of an Echo Nest-based recommendation app for Spotify told us he's working on an official version for Spotify's consideration. For developers who want to start coding apps for Spotify, Music Machinery has a detailed introduction to the process. Be warned, though: for now the company is not offering any kind of revenue share to developers, as all apps are free to install.

The digital music space is a busy place these days, from tech giants launching cloud storage lockers and streaming services duking it out, to developers all over the world participating in music hack days and building new and interesting things everyday. As Spotify grows into its new role as a platform, we expect to see nearly limitless new integrations and features added as time goes on.

I never abandoned purchasing music all together, but the MP3 struck me as a far more convenient format than the compact disc, and Napster gave me quick and easy access to a world of MP3's. When Radiohead's "Kid A" showed up on Napster weeks before the CD was available in stores, what was I supposed to do? Ignore it?

The Napster brand lived on for years to come, having been converted to a pay subscription music service. Unsurprisingly, it never quite returned to the levels of popularity it saw in 1999, as new digital music services popped up left and right. Most recently, the company was purchased by one of those services, Rhapsody. Today, Napster will officially be absorbed into the Rhapsody brand and even that iconic, headphone-wearing logo, once a symbol a generation's digital defiance, will cease to be used.

Ten Years After Napster, Digital Music is Still Evolving

As we head toward 2012, the digital music landscape looks very different, and in fact is still evolving into something that works well for fans, music labels and artists alike. The record industry as we once knew it may never return, but that's not necessarily a bad thing. Today, people can record multi-track demos on the tiny computers they carry in their pockets and produce complete, studio-quality tracks on their laptops later. Once everything is mixed and mastered, they can publish it online audience at little to no cost.

Naturally, DIY artists who get started on the Internet don't have quite the reach of a record label, but many musicians have launched their careers online and some established artists have relied on the Web in lieu of the record labels that once supported them.

Consuming Music is Even Easier Without Napster

As far as consuming music, it's never been easier. Just as one used to be able to find new albums on Napster or LimeWire within days of their release, most major label and indie releases are available on Spotify, Rdio or MOG pretty much right away. If not, you can try Grooveshark, as long as it's still around, anyway. If those freemium streaming sites don't have what you're looking for, Apple, Google and Amazon all have massive MP3 stores with cloud-based storage services alongside them.

In addition to being legal, today's digital music services go beyond the desktop and are readily available on our smartphones, those little gadgets could have hardly imagined a decade ago. They're even starting to get integrated into smart TVs, cars and a growing number of household appliances.

For a more serendipitous listening experience, there's personalized Internet radio services like Pandora, Last.fm and Slacker Music. If you prefer human recommendations over algorithms, services like Shuffler.com scan hundreds of popular music blogs and build genre-based, curated music stations, even on the iPad. You can even listen to others DJ their own setlists in real time using services like Turntable.fm or one of its many copycats.

Of course, if none of these options give you what you're looking forward, less-than-legal means to acquire music still exist, but you didn't hear it from us.

Music is still a huge - and growing - part of the Web today. This year, we watched a number of trends unfold in the digital music space. Picking the five most significant was no easy task, but we manage to narrow it down. This space is still evolving, and we can only imagine how it will look another decade from now.

Buzz about "the cloud" in general has been building up for a few years now, but 2011 was the year that we saw our music collections begin to make their way toward Web-based repositories. First, there was the rise of all-you-can-stream music services like Rdio and Mog. That particular space was lit afire by the July U.S. launch of Spotify, which did not go unnoticed by its competitors, most of whom dropped their entry level price tags down to zero in order to keep up.

With these services, consumers move from playing MP3s on their hard drives to streaming tracks from the cloud, whether at their desktop or from their smartphones and tablets. In the case of Spotify, that cloud-based library of millions of tracks can even be merged with one's own local collection, providing a theoretically infinite library of music.

This year, we also saw the emergence of cloud music lockers. This model is a bit different from the streaming services in that it takes a person's existing collection and allows them to store it online for playback from any connected device. Amazon launched their Cloud Drive in late March, having already operated their own MP3 store for some time. The service allows music fans to upload and store their collections to Amazon's servers for streaming later.

Amazon's model is quite similar to the one offered by Google about eight months later when it publicly launched Google Music. The new initiative, which was first unveiled at Google I/O in May, took the cloud music locker concept the company originally built and added a digital music store on top of it, putting the service in direct competition with Amazon Cloud Drive.

Not to be left out of the cloud music game, Apple unveiled iTunes Match alongside iOS 5 and iCloud in June. Ten years after the company began revolutionizing digital music with the iPod, Apple decided to place a big bet on the idea that the cloud is where people will store their ever-expanding music collection in the future. Like Amazon and Google's solutions, iTunes Match enables access to one's collection across devices. Crucially, Apple's offering does not support streaming, but rather requires listeners to download tracks locally.

2. Online Music Gets More Social (or Annoying)

For as long as there have been Web music services, there have been attempts to bolt on social networking features. Some, like the Ping feature in iTunes, have fallen flat. Pandora has managed to become a relatively successful service without baking in very many social features at all. By comparison, Last.fm and Rdio are way more social.

As popular as it is in Europe and now the U.S., Spotify never had any ground-breaking social features of its own; Just the ability to share playlists and tracks over Twitter and Facebook and plug into other services like Last.fm. That all changed at the f8 developer conference in September when Spotify became one of a number of music services to get tight integration with Facebook.

Rather than try and take on Google, Amazon and Apple and smaller players in the music space, Facebook decided to partner with the likes of Mog, Rdio and Spotify to advance it's so-called "frictionless sharing" philosophy. By linking their Facebook account with any one of these services, users can automatically share every single track they listen to with their Facebook friends and start amassing aggregate monthly data about their listening habits on their Facebook profile.

The partnership has helped fuel enormous growth for Spotify and delighted some users, but not everybody is thrilled with the concept. CNet's Molly Wood wrote a biting critique of Facebook's new approach to sharing, and our own Marshall Kirkpatrick weighed in with a thoughtful critical analysis. ReadWriteWeb founder Richard MacManus had some concerns about it as well, but thinks Facebook is simply redefining sharing, rather than flat-out ruining it. Scott M. Fulton III reminded everybody that these features require users to opt-in, so avoiding the discomfort is as easy as doing nothing. If you've already connected Facebook and Spotify, but have had a change of heart, you can always turn the integration off.

Love it or hate the execution of it, Facebook's integration with music services is just the beginning of a more social experience when it comes to listening to and discovering music online.

3. Recommendation Evolves: Man vs. Machine

Digital music recommendation engines are nothing new. Pandora and Last.fm have provided listeners with algorithmically-determined suggestions for years. In 2011, as new music services cropped up left and right and the selection of available music continued to expand, listeners still found themselves with a thirst for solid recommendations for what to listen to next. Pandora, which filed for a $100 million IPO in February, continued to serve as an attractive Web radio option, with its powerful recommendation engine fueled by the Music Genome Project.

Even though it's overshadowed by the newer, all-you-can-stream music services, Last.fm still boasts a robust community and its music recommendation algorithm is often used by other apps (including Spotify), from which users can "scrobble" their music, creating a detailed profile of listening habits that can be used to discover similar artists.

A music recommendation system many have used, often without knowing it, is The Echo Nest. Their platform powers dozens of music apps with over 5 billion data points about music and various associations between different artists, albums and songs. To date, the Echo Nest Platform has indexed over 30 million songs, far more than Pandora.

As powerful as these machine-driven recommendation engines can be, there's still something to be said for human curation. For evidence of this, look no further than the popularity of apps like Shuffler.fm, a service that turns human-edited music blogs across the Internet into dynamic, genre-based radio stations. It takes a step away from the algorithm in favor of tastemakers, kind of like in the old days. Shufflr.fm received heaps of praise from the tech press over the summer and recently launched its iPad app, making unique music discovery experience portable.

4. Group Listening: Turntable.fm and Beyond

The value of this human touch in digital music curation was also seen in the rise of group-listening apps in 2011. The biggest and most buzz-worthy was Turntable.fm.

When the creators of mobile barcode scanning app Stickybits decide to pivot, as they say, to an entirely new type of mobile application, they didn't expect it to blow up quite the way it did. Turntable.fm, their virtual group-listening and DJ'ing Web app, became wildly popular and sparked several copycat sites, including one that was a near total rip-off of the original.

Turntable.fm allows users to get together in a virtual room and take turns playing DJ for one another, using music stored on their computer's hard drive. In September, the company brought this group listening experience to the mobile space when it launched an app for iPhone and iPad.

5. Music Creation Goes Mobile

It wasn't just music consumption that got a big boost in 2011. Creating it is now easier than ever, thanks to a growing array of digital tools.

Mobile apps geared toward creating music started appearing shortly after the launch of the iTunes App Store in 2008. As platforms like iOS and Android have grown more capable, so too have these kinds of applications. There's no shortage of apps that synthesize real instruments, and even ones that let you record your own samples, make beats and create songs from scratch.

In 2011, we saw Apple roll several of these concepts into one when it launched Garage Band for iPad, and then scaled it down for the iPhone and iPod Touch. It's not the first music recording and sequencing mobile app to appear, but for the price tag ($4.99), it's easily the most powerful. Garage Band for iOS includes dozens of synthesized instruments, which can often be pretty expensive when purchased as stand-alone apps. It also has several "smart" instruments for the less musically inclined.

Like its desktop counterpart, the core function of this app is to record and sequence multiple tracks of music. Using external accessories, one can even record vocals and guitars. Garage Band for iOS and apps like it provide an early glimpse of what's possible on tablets and smartphones, two categories of devices that are still relatively young.

It was a good year for SoundCloud, a social audio-hosting site that has grown quite popular among amateur and professional musicians alike. Big labels and known acts are using SoundCloud to post and promote music, while smaller artists and laptop hobbyists are finding audiences there as well. Think of it as sort of a YouTube for audio.

Like so many other popular Web services, SoundCloud pushed further into the mobile space this year, launching apps for iPhone, Android and iPad, among others. Users can not only use the service's mobile apps to stream and comment on music, but they can also record and post their own tracks right from the app.

Developers have already built apps with features like the ability to find and purchase concert tickets, the means to display a song's lyrics on-screen through TuneWiki and deeper Last.fm integration for better music recommendations.

The move attempts to rebrand Spotify as more of a platform, much as Facebook once did when it opened up the ability for developers to build applications on top of the social network. It's a wise move for Spotify, which faces a rapidly-expanding user base and only a limited capacity to roll out new features itself. By opening up its platform to developers, Spotify allows for more rapid innovation without distracting itself from the core product.

Other available apps include SongKick, The Guardian, Billboard and Soundrop, presumably with plenty more to come. Any developer can code apps for Spotify but they do have to be approved by the company before appearing in the directory.

Slowly Opening Up Spotify's Walled Garden

The catch? For now, the new third party apps are only available on the desktop client, although Ek did indicate that popular features would find their way onto the company's mobile apps.

There's no word on whether the same JavaScript API used by Spotify app developers would be available to everyday Web developers. This would enable music publications and other music-related websites to create an experience much like Rolling Stone has done from within Spotify, but they could do so on the open Web. Of course, one of the obstacles to a seamless experience is the fact that Spotify does not have a Web app of its own, requiring a native desktop or mobile application for song playback.

Spotify first launched in the United States in July, after a prolonged and anxious wait by American music fans, who had been hearing more than a little buzz about the European music service. Today, the company has 2.5 million paying subscribers, Ek said.

Today's announcement comes just two weeks after the public launch of Google Music and Apple's iTunes Match. While neither service is a director competitor to Spotify's freemium streaming model, the two tech giants are inching closer to the space and upstarts like Spotify need to be on their guard.

Sometimes it's difficult to catch every story that hits tech media in a day, so we wrap up some of the most talked about stories. We give you a daily recap of what you missed in the ReadWriteWeb Community, including a link to some of the most popular discussions in our offsite communities on Twitter, Facebook, LinkedIn and Google+ as well. This is a new feature at ReadWriteWeb so we covet your feedback. If you have suggestions, please leave them in the comments below or reach out to me directly at robyn at readwriteweb.com.

ReadWriteWeb has covered Facebook's Frictionless Sharing several times, with passionate responses from our readers, so there's no surprise that today's top story also involved an issue with Frictionless Sharing. John Paul Titlow finds the automated sharing via the Spotify integration to be overwhelming in quantity but lacking in usable information.

From ReadWriteWeb community member, Franco J. Torres:

Here are a few more must read posts, chosen by your fellow community members.

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Android May Dominate the Numbers, But iPhone Most Desired

Comments from Caio Iglesias, Sebastián Ventura and ReadWriteWeb writer, Dan Rowinski:

The Four Degrees of Separation on Facebook

Comment from Jeff Yablon and ReadWriteWeb writer, David Strom:

Stamped For iPhone Gets Rid of 5-Star Ratings, Google Ventures Approves

Comment from Mosaic Technology:

Courseware for Security Noobs

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How Google Apps Can Help You Unplug for the Holidays

Comment from Lexingtonian:

Forrester: VDI, PaaS Technologies Stuck in the Gestation Phase

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An early and central component to this new type of all-or-nothing sharing is Facebook's integration with Spotify and similar music streaming services. In theory, it adds a useful new social layer to the experience of listening to music online. In practice, however, it's not well-executed enough for me to keep it activated.

Yesterday, I logged into Facebook and saw that my friend James had shared a song I hadn't heard. It was a collaboration between hip hop artist MF Doom and two members of the band Radiohead, hosted on Soundcloud. The link was shared manually and deliberately with a note reading, "This is awesome."

This type of curated, intentional sharing is what makes social networking useful. I knew that a friend of mine had not only listened to the song, but that he especially liked it. And it was just one song. Not several dozen.

What's far less useful to me is seeing that my friend Evan listened to two entire albums on Spotify, or that my friend Kait is apparently listening to her entire library on shuffle. While some of this information has value, a constant flow of it just amounts to noise.

The Data is Excessive, But Still Not Comprehensive

Even though Spotify spews a massive amount of data onto the news feeds of my friends on Facebook, it's still not a comprehensive representation of what I'm listening to each day. I happen to use the Spotify desktop client and mobile apps for most of my music consumption, but many do not. They still have a library in iTunes or a Windows music app. For those people, something more akin to Last.fm's scrobbling feature would provide a more thorough representation of their listening habits, which on the whole could paint a bigger picture and make an interesting addition to their Facebook profile.

Yet even for those of us who exclusively use Spotify, the picture is not complete. Facebook will post an update about every song I listen to that happens to be in Spotify's streamable library, but not the songs I have stored locally on laptop. This is a side effect of the way the integration works; If the song isn't hosted on Spotify's servers, my friends can't listen to it from Facebook. So perhaps it doesn't make sense to post each song to the news ticker, but Facebook could still make a note of it every time I listen to The Beatles or a less well-known band that isn't available on Spotify.

So-and-So is Listening to Such-and-Such, But Nobody Else Cares

Perhaps for a certain cross-section of music fanatics and people you're friends with on Facebook, what you're listening to right this very moment might be of some interest. But for the vast majority of people on your friends list, it doesn't matter. To many of them, seeing a constant flow of songs in the news ticker is at best irrelevant and at worst annoying.

When people check in to bars, restaurants and other venues on Foursquare of Facebook places, there's value in that. Even better if they add a sentence or two about their experience. Imagine if instead of "Dan is at Oscar's Tavern" you saw a flood of updates saying things like "Dan is walking down Chestnut Street" and "Dan just turned the corner." You don't care about every single physical location your friends inhabit (which is why Apple's Find My Friends app is so weird). But you might care if they're at the baseball game or a restaurant they highly recommend.

Similarly, most people don't care or need to know about every single song you listen to, or every news article you read.

How the Experience Could Be Better

This isn't to say that the data Facebook is collecting and publishing isn't potentially valuable. Some of the aggregate information found on Facebook's music dashboard is worth looking at. That's where I can see things like which songs are most popular among friends and which artists are being enjoyed by multiple people I know. Even much of the summary data Facebook posts to my Timeline is useful. For example, a monthly or weekly digest of top tracks or artists would make sense on one's Timeline.

If instead of barraging other users with real-time activity data, Facebook's music integrations displayed the information in a more measured way, I could see keeping Spotify and Facebook connected. The social giant is trying to reposition the user profile as a timeline of one's life, including as much information as possible. I like this idea, but for it to work, some kinks need to be ironed out in the current, so-called frictionless model.

ST Holdings, a music distributor that represents over 200 labels, recently asked those labels if they would like to keep their catalogues on services like Spotify and Rdio. Four of them said yes. So, citing a recent survey showing that streaming services hurt music sales, ST Holdings pulled its music from Spotify, Rdio, Napster and Simfy.

200 Music Labels Sounds Like a Big Loss...

The ST Holdings labels weren't the first to pull out of the digital streaming business. A number of small, independent labels have done so and recently bigger acts like Coldplay have declined to make new material available on Spotify.

While 200 music labels sounds like a lot of content, it's worth noting that these are also relatively small labels, most of which specialize in various sub-genres of electronic music. There's very little risk of any of the major labels dropping Spotify, event if a few big name artists with enough clout may follow Coldplay's lead.

In addition to the four (okay, three) major labels, Spotify and its competitors still have most of the bigger independent labels, including more than 12,000 represented by Merlin. For the time being, the majority of popular artists, both mainstream and indie, are available on Spotify.

You Can Still Get Any Music You Want and Put it in Spotify

When Spotify finally launched in the U.S. this summer, I put it through its paces for about 48 hours, and then signed up for the premium account, dropping Rdio in the process. As much as I liked Rdio (and still miss its UI sometimes), one of the killer features of Spotify had for me was its ability to merge my locally-stored music files with its giant library in the cloud.

The truth is, I don't expect every artist on the planet to be included in Spotify's library. As long as a sizable (and growing) selection of artists is there for me to stream, I'm perfectly content acquiring other music directly, especially from local artists who may not be signed to even a tiny label.

When I do, I can download those files to my laptop and listen to them from the same desktop client I use for streaming. When I sync my iPhone and iPad with Spotify, that music is then transferred to those device and is available to me when I'm on the go.

The Music Industry is Still in Transition

Ten years after the demise of Napster, the music industry is still very much in transition. What will have emerged another decade from now is going to look different from what we know today and the shift probably isn't done being disruptive.

To be sure, the concerns artists have over the low payments offered by all-you-can-stream model are perfectly legitimate. It's undeniable that direct downloads and even physical music format sales generate more revenue than services like Rdio and Spotify. However, Spotify has only been live in the U.S. for four months and is still growing. As that happens, its competitors are adapting. In time, the model should become more profitable for arists Both Apple and Google have also stepped up their game in the digital music space recently.

Just as I, as a consumer, have multiple ways to legally acquire music, artists have several choices when it comes to selling and distributing it in this new digital ecosystem. Streaming services are one of them. iTunes and Amazon's MP3 store are others. As of last week, artists can now upload their own music directly to Google Music and set their own prices. Similarly, tracks can be sold via Bandcamp.

Even with these options, it's possible that the recording and distribution of music may not forever be as lucrative as it is today. Tomorrow's model may include a hybrid from music sales, merchandise, performances and perhaps other factors that have yet to fully emerge.