Now, however, according to the latest data from HubSpot, Twitter's growth is slowing dramatically. In October 2009, Twitter's growth rate had fallen to 3.5%. On a positive note, though, the average active user on Twitter today is more engaged than six months ago.

Most Twitter users, however - even if they are now more engaged on average - still have fewer than 100 followers. Only 18% of all Twitter users have more than 100 followers. A total of 81% of all users are currently also following less than 100 people. Just six months ago, the average user was just following around 40 accounts.

HubSpot's analysis also shows that more Twitter users now include bios (54%), links (65%) and location data (41%) in their profiles.

International Footprint Increases

As we pointed out earlier this month, social media analytics firm Sysomos also noted that most of Twitter's growth is currently happening internationally. According to HubSpot's analysis of over 5 million Twitter accounts, 40% of the top 20 Twitter locations are now outside of North America. In July 2009, only 15% were from outside North America.

For Twitter, this means that its current user base is making better use of the service, but the company also has to worry that its growth is slowing down. Maybe some of the earlier high growth rates were inflated by spam accounts, but a 3.5% growth rate is very low and the overall trend is only pointing down at this time.

According to a post on Nielsen Wire, unique visitors to Twitter.com increased 1,382 percent year over year, from 475,000 unique visitors in February 2008 to 7 million in February 2009. This growth earned it the title of "fastest growing member community site," a term that encompasses not just social networks but any online community - even one such as online wiki community Wikia, which, incidentally, came in at number five on the list. Zimbio and Facebook followed Twitter, growing 240 percent and 228 percent, respectively.

Nielsen also reported that the largest age group on Twitter was not college students or teens, but adults from the ages of 35-49. This group comprises nearly 42% of the site's audience at 3 million unique visitors. Twitter is also a popular site for people to visit while at work, notes Nielsen's Michelle McGiboney, as 62% of the combo unique audience accesses Twitter.com from work versus only 35% from home.

Of course, visitor stats to Twitter.com from a traditional web browser don't show a complete picture since the service is also accessible from a number of desktop and mobile clients as well as SMS. In January, 735,000 unique visitors hit Twitter's mobile web site, averaging 14 visits per month and spending an average of 7 minutes per visit. Twitter also had 812,000 unique users sending and receiving text messages in the last quarter of 2008. However, this last stat only took into account AT&T and Verizon cell phones. Within that group, though, there were nearly 240 tweets per person for the quarter.

A Word About These Numbers

Before taking these numbers to the bank, it's worth noting that they are being pulled from Nielsen NetView (U.S. Home & Work), so they're not representative of the service as a whole - they only give us a snapshot of what's occurring there. Also, the demographic chart is annotated with a note that reads "these demographics have insufficient sample sizes" in the 18-24 age group column, which may speak to the overall insufficient sample size of this particular survey, a number which was not reported.

That said, these numbers do seem to confirm what our gut instincts have been telling us for some time. Twitter is apparently not becoming the next big thing with teens and other members of Gen Y, despite rumors to the contrary. The hype surrounding Twitter's connection to the younger generation was even skewered hilariously by Jon Stewart not too long ago on "The Daily Show."

It looks like Twitter may be for "old people" after all. Just like Facebook.

If Facebook continues at this rate, by the end of December they could add a total of 20 million new users. By March, the company could then reach 200 million active users - which would mean they doubled their userbase in less than a year's time. The majority of this growth (70%) is taking place outside the U.S.

To handle this growth, a poster on Slashdot notes that "the Facebook engineering team has been tweaking its use of memcached, and says it can now handle 200,000 UDP requests per second. Facebook has detailed its refinements to memcached, which it hopes will be included in the official memcached repository. For now, their changes have been released to github."

Facebook's Users Are Active and Engaged

Facebook did release some figures of their own today that show their users are actively using the site and engaged with the content. Here's what they reported:

General Growth

• More than 140 million active users
• More than half of Facebook users are outside of college
• The fastest growing demographic is those 25 years old and older

User Engagement

• Average user has 100 friends on the site
• 2.6 billion minutes are spent on Facebook each day (worldwide)
• More than 13 million users update their statuses at least once each day
• More than 2.5 million users become fans of Pages each day

Applications

• More than 700 million photos uploaded to the site each month
• More than 4 million videos uploaded each month
• More than 15 million pieces of content (web links, news stories, blog posts, notes, photos, etc.) shared each month
• More than 2 million events created each month
• More than 19 million active user groups exist on the site

International Growth

• More than 35 translations available on the site, with more than 60 in development
• More than 70% of Facebook users are outside the United States

Platform

• More than 660,000 developers and entrepreneurs from more than 180 countries
• More than 52,000 applications currently available on Facebook Platform
• 140 new applications added per day
• More than 95% of Facebook members have used at least one application built on Facebook Platform

Also worth noting is the data on mobile users released last month which revealed that the company has 15 million active mobile users using their site, having grown from only 5 million at the beginning of the year. Those aren't additional users, but are a subset of the 140 million who use the site from their mobile phones and other devices. We can't help but think those numbers were also aided by the September launch of Facebook's iPhone app, version 2.0. The new release, a huge improvement over the original, managed to pack in nearly every feature from social network including wall posts, status updates, the news feed, photos and more, all from the simplified iPhone interface.

How to Get More Stats

If you like delving into statistics or are just looking for specific information on Facebook demographics, the AllFacebook site has a pretty handy online tool available. With it, you can use drop-down boxes to select country, gender, and age range and have the tool chart that data on the screen for you. You can compare up to three companies using this tool.

Image credits: top chart, Inside Facebook; bottom chart, AllFacebook

According to the article, Facebook saw a 5% drop between December, 2007 and January, 2008, but still had 8.5 million users in January. This keeps Facebook in the number one position as the most popular social network in the U.K. However, after 17 straight months of growth, this drop of 400,000 users, is the first on record for Facebook in the U.K.

MySpace also lost 5% drop in traffic between December and January. They are still the number two social network in the U.K. with 5 million unique users.

Bebo only saw a 2% drop, and ranked third with a total of 4.1 million users.

Growth Rates at an End?

These drops in growth, if anything, point to the fact that the massive growth rates the networks were experiencing could not be maintained indefinitely. For example, Facebook's audience is 712% bigger than it was in January of 2007 and Bebo saw a 53% increase in the same period. I would argue that these numbers point to the networks being more popular, not less, than they were a year ago, so I'm not sure what Burmaster meant in that earlier statement unless he was solely referring to growth rates.

However, Facebook and Bebo's growth may have come from MySpace's loss. The News Corp. giant actually saw its number of unique users fall by 9% since January, 2007. Says Burmaster, "Growth among the big players looks to be more about getting people from their competitors, not attracting new people to social networking."

Does these findings foretell a saturation point for social networks? Or are the networks just not that cool anymore now that everyone uses them? In a BBC News article on the subject, Nic Howell, deputy editor of industry magazine New Media Age claimed, "Social networking is as much about who isn't on the site as who is - when Tory MPs and major corporations start profiles on Facebook, its brand is devalued, driving its core user base into the arms of newer and more credible alternatives."

Interestingly enough, the exodus from the larger networks may have had an impact on some of the smaller networking sites that grew during the month of January. Less trafficked social networking sites like Windows Live Spaces, which just launched a refreshed version with some Facebook-like features, saw a rise in number of users at this same time. Other U.K.-oriented sites like BBC Communities and Friends Reunited also saw growth in January.

Update: A Facebook spokesperson contacted me this afternoon with the following: "The number of users for Facebook continues to climb in the UK. Our internal monthly active user numbers rose between December and January in the UK and are now at more than 8.3 million. Facebook tracks active monthly users, rather than registered user or unique visitors. Active users reflect those who have used the site in the past 30 days."

In other words, "you're measuring the wrong thing."

How about year over year growth? Facebook had 10.59% marketshare in December 2006, Hitwise says. Myspace dropped from nearly 79%. It appears that social networking has grown in general; though Facebook posts impressive numbers of new users, in terms of sheer visits Myspace is nearly keeping up with its growth.

If we assume that Facebook is growing rapidly then the relatively similar marketshare numbers year over year indicate it's actually the entire sector that's growing. Though trailing in the distance of the big two, market share percentages have held steady or grown for the next services in line as well: Bebo, BlackPlanet, ClubPenguin, GaiaOnline, MyYearbook and Hi5 have unchanged or increased marketshare numbers according to the same metric.

Chart from Hitwise

The Hype

Tech bloggers write about Facebook all the time, I feel like every coffee shop I visit is filled with laptops open to Facebook and Richard MacManus (in transit to the US as we speak) says he just saw a whole magazine about Facebook in the airport. CEO Mark Zuckerberg was on 60 Minutes last weekend, interviewed by a reporter who marveled at the most basic social networking functionality.

The Facebook platform, valuation and scandals have all caught the imagination of much of the press. Many of our readers, however, are less thrilled with the direction Facebook is going. Two of our most popular posts of late were an interview with a disgruntled early Facebook user and our coverage of the just released Facebook feature that lets users hide the overhyped applications in their profile!

Tom's Still Got Friends

Meanwhile, millions and millions of people are still happily logging into MySpace to communicate with their friends. I spent some time on MySpace last night, exploring the profile pages of family and friends and was shocked to see that all the music players on the site are now sponsored by Zune. It was news to me but I'm told it's been that way for weeks. I haven't been able to find a single shred of coverage of that deal on any of the top tech blogs - but I would assume it's helping sell more Zunes than ever.

Numbers like those from Hitwise always need a grain of salt, but the next time someone tells you "by this time next year, everything you invest in will be built on top of Facebook," (as Tribe.net founder Mark Pincus reportedly told Fred Wilson last year) - you just send them over here to this post and then see what they say.

Facebook is interesting but Myspace is where the users are, still.

Is Classism Part of this Story?

It's entirely possible that people actually know about this already, but that the technocratic classes are excited as they (we) are about Facebook for another reason. Money. It's been documented and is generally understood that Facebook users tend to come from wealthier demographics that are more invested in the high-end economy than are Myspace users.

There has certainly been a lot of innovation at Facebook, and that innovation is more accessible to developers than the still-forthcoming Myspace Platform, but how much of this excitement about Facebook is really grounded in the perception that it's the Junior LinkedIn - the path to yuppie pockets. If people mock niche social networks aimed explicitly at wealthy or upwardly mobile people - why is it more polite to focus on a social network widely understood as yuppie-focused (Facebook) as the future of everything important on the internet? How often does the press pay attention to BlackPlanet.com? Not very often, as far as I can tell.