For some of us, watching YouTube on a mobile device is an additional way to watch video, not the primary way. But as it turns out, for a large majority of mobile video users, it's completely the opposite.

As noted by the Google Mobile Ads blog post reporting this data, these figures aren't really a surprise. It referenced a recent Nielsen survey that found that YouTube Mobile is the number one mobile video viewing site in the U.S., with more than 7.1 million uniques.

Of course, Google is revealing this news to get at mobile advertisers - the post mentions that advertisers can now buy a "daily roadblock" which allows them to own all available ad impressions for 24 hours. Those ads would run on the Search, Browse and Home pages of the mobile website.

Obviously, that's a great way to reach a wide audience of video viewers in the U.S., but advertisers should realize that these are only the viewers who head to the website m.youtube.com. As described on the Advertising page for this product, the roadblocks reach those who "engage with the mobile site on the homepage, browse and search pages from any mobile device including Android, iPhone, Blackberry, and feature phones."

Browse and search pages, it says. Web pages, not apps.

The blog post's image depicts a recent campaign for Diet Coke on top smartphones including the iPhone, Blackberry and Android. However, on these devices, YouTube viewers have access to native applications pre-installed on their phones. Wouldn't it be fair to assume that more streams come through those apps on the smartphones? How much of the smartphone audience is being targeted when you buy an ad on m.youtube.com? We've reached out to some mobile video experts to further research this and will collate our findings into a future post on ReadWriteMobile. Stay tuned.

On Smaato's network, which handled about 16 billion ad requests last month, click-through rates for the iOS platform saw strong growth last month. The reason for this change in user behavior is not clear, but maybe the arrival of more interactive ads on the iOS platform (and the iPad in particular) tempted more users to click on ads than before.

Of course, besides the different user experiences on these platforms, user demographics also play an important role here as well. In general, the more highly educated your users are, the less likely they are to click on ads, and this is clearly represented in Smaato's CTR data for the top mobile platforms.

Bonus: A Mobile Advertising Primer

Smaato also just published a new whitepaper that provides both publishers and advertisers with a good overview of the mobile advertising ecosystem and the role that ad optimizers like Smaato play in this business.

Medialets has already partnered with well-known publishers to help launch mobile ad campaigns on Android devices. Earlier this year, New York Magazine launched an Android application with a featured set of Starbucks advertisements built on the Medialets Android SDK. Other publications, like the New York Times, Washington Post, CNN and NPR have also taken advantage of Medialets in the past.

Medialets already provides a Universal SDK for iPhone and iPad, giving advertisers a wide network of options for mobile ad initiatives. As the company points out, combining campaigns on both networks using both SDKs is an effective way to reach a wide audience of smartphone users. Medialets also provides analytics that allows publishers to view stats on their efforts across all supported platforms.

Advertising on the Android platform is looking more and more attractive as Apple tightens restrictions for ad networks operating on iPhone and iPad applications. As more publishers look to serve ads to more devices, Medialets is emerging as a popular platform on which to launch their campaigns. With other mobile ad networks creating competition - like Pinch Media and Mobclix - it may be the cross-platform solutions that garner more attention from publishers.

In figures just released from mobile advertising company AdMob, the Droid singlehandedly boosted calls to their network by nearly 300 million requests while stats for HTC Magic devices remained static and those for HTC's Dream model actually decreased. In terms of consumer use of the network and acceleration of device popularity, it seems we have a winner.

AdMob's numbers show that requests from all Android-driven devices increased by 97 percent between October to December in 2009, totaling more than 1 billion requests in December alone.

The open platform has also seen a refreshing diversity of devices and manufacturers. AdMob shows that in December, 56 percent of requests were from HTC devices, 39 percent were from Motorola devices and 5 percent were manufactured by from Samsung. And in December, seven devices generated more than three percent of requests each: the Motorola Droid, HTC Dream, HTC Magic, HTC Hero, Motorola CLIQ, HTC Droid Eris and the Samsung Moment. This stat represents a significant increase from just three devices in October (HTC Dream, HTC Magic, and HTC Hero).

Already, the Motorola Droid is the leading Android device on AdMob's radar, generating a third of all the network's requests in December. Released just under two months ago, it's already the top-selling Android device on the market, a title it's held since a scant fortnight after its launch.

Granted, AdMob's metrics show a small slice of mobile device usage. But they've consistently been reliable in showing what mobile users use and need and in predicting trends. We are internally excited about what Android-powered devices will do in the market in the months to come, and I am personally quite optimistic about Droid adoption specifically.

Let us know what you think in the comments, particularly if you're a fanboy or fangirl of a particular device!

With these levels of growth, we're also seeing related mobile services getting a boost. App stores, both phone-based and carrier-based, are popping up left and right, mobile video usage is booming, and mobile ad markets are seeing dramatic growth, too. However, there's one area that hasn't yet benefitted from the mobile revolution: mobile e-commerce.

The indicators of increased mobile web usage are everywhere. Just this week, we heard Facebook reporting their mobile growth had tripled from December of last year to this past month, for example. And then there's AT&T, the carrier for Apple's iPhone, which is seeing so much data usage that they couldn't even keep up, having to delay the introduction of new iPhone capabilities like MMS messaging until they were ready to handle the demand.

Mobile Ads Doing Well

Mobile-dependent markets are doing well, too, at least for the most part. A recent Gartner report states that mobile ad spending will grow 74% this year worldwide to $914.5 million. But the real growth won't happen until 2011 when advertisers are expected to fully embrace the shift to mobile. By 2013, the firm expects the mobile ad market to surpass $13 billion with the Asia-Pacific region in the lead, followed by North America and Europe. Not only is the rise of the smartphone to thank for this trend, so is the rise in flat-rate data plans which make it easier for more consumers to afford mobile web connectivity. As more consumers go online, more web publishers begin to cater to their needs with mobile-ready versions of their websites. This, in turn, "is lifting mobile web access among non-smartphone users," notes Gartner analyst Andrew Frank.

Mobile Video on the Rise

Along with basic web surfing, mobile users are also finding entertainment via their handhelds, specifically in the form of mobile video. According to Nielsen's latest three-screen report, the number of people watching mobile video increased 70% from last year. Nielsen, which specifically tracks American media habits, says this increase to 15 million viewers represents the largest annual growth to date.

M-Commerce Struggles

However, not all mobile-dependent markets are doing well. Mobile e-commerce, for example, is struggling. Despite the massive numbers of mobile users, those using their phones to make purchases are still few and far between...at least here in the U.S. According to new data from eMarketer, more than 70 million U.S. mobile phone users will access the internet from their devices this year, but the m-commerce market remains immature. In an April 2009 survey by RIS News, privacy and security concerns are still at the forefront of both shoppers' and retailers' minds. This had led companies to drag their feet when it comes to introducing their mobile commerce plans. Says Jeffrey Grau, eMarketer senior analyst, "most retailers are either standing on the sidelines or in the midst of planning their mobile commerce strategy."

Another major problem is the lack of standardization in the mobile space. With the number of platforms now available, retailers find building a plethora of mobile applications not worth the effort. As InfoWorld recently noted, the smartphone market has become a "tower of Babel for developers." This means that mobile retailers have to carefully pick-and-choose the platforms they plan to support in order to see reasonable returns on their investments in this space. Despite the slow growth, it appears that m-commerce could be successful if only there were enough mobile apps and shopping opportunities out there.

Already, mobile payments firm Billing Revolution found that on-the-go consumers seem happy to purchase small ticket items like pizza and movie tickets, for example.

And a March 2009 PriceGrabber.com survey found that early m-commerce adopters were even buying up higher priced items like consumer electronics, apparel and jewelry.

In other words, when it comes to m-commerce, "if you build it, they will come." , or so it seems. However, developing m-commerce applications is only one part of the equation. For mobile e-commerce to be successful, we'll need to adopt a number of mobile payment platforms too.

"Mobile advertising is rapidly maturing, and we believe the iPhone is leading the industry forward. Advertisers are excited to connect with consumers in new ways on the iPhone through social and rich media ad units that deliver increased impact and engagement," said AdMob VP/GM, Jason Spero. The new ads build on the high-performing iPhone ad units the
company launched last year and will begin running July 1st.

AdMob is also working with app developers to help them prepare for the new iPhone 3.0 OS. The company feels their new version of the iPhone SDK "delivers a better experience for consumers through the ability to dynamically update a given advertisement's look and feel, which in turn helps developers better monetize their applications," according to the company's press release.

As we reported last week, the iPhone/iTouch group of smart mobile devices accounted for 43 percent of ads served via mobile websites and 65 percent of ads served through HTML requests.