The Network Effect: Facebook, Linkedin, Twitter & Tumblr Reach New Heights in May

While it is perhaps not surprising that social networking continues to gain market share, what is interesting is the rapidly changing dynamics of the market today. For a long time, the social networking story was almost exclusively the horserace between Facebook and Myspace. In mid-2009 Facebook finally darted out ahead of Myspace and hasn’t looked back.

Today Facebook is the 4th largest U.S. web property in audience size with 157.2 million visitors in May, representing its all-time high and a gain of 3.2 million visitors vs. the previous month. While other reports have been circulating that Facebook witnessed a pronounced user decline this month, Comscore data shows quite a different story. Given that Facebook now reaches 73% of the total U.S. Internet population each month, one thing we should anticipate is that the site’s audience cannot grow forever. The law of large numbers says that once a site has penetrated the majority of a market, each incremental user becomes that much more difficult to attract. So given its size, Facebook’s future U.S. growth is likely to come more from increasing usage per visitor than its ability to attract new users in perpetuity. One impressive stat to note is that Facebook’s average U.S. visitor engagement has grown from 4.6 hours to 6.3 hours per month over the past year, so it appears to be succeeding in that regard.

The picture is not so rosy for Myspace, which continues to see attrition in its U.S. user base. While it is currently holding onto its #2 position among social networking sites with 34.9 million visitors in May, its audience has declined by nearly 50% in the past year while average user engagement has dropped 85%.

So perhaps it’s time to turn our focus away from the Facebook-Myspace horserace for a moment and focus some attention on other players in the market deserving of mention. Upon the release of Comscore’s May U.S. data, I immediately noticed that it was not just a banner month for Facebook but also for several other leading players in the social networking category who also reached all-time U.S. audience highs: Linkedin.com (33.4 million visitors), Twitter.com (27.0 million) and Tumblr.com (10.7 million).

Beginning with Linkedin, the popular business networking site’s success should not come as a complete shock following its blistering May 19th IPO. Others can debate the merits of the company’s current valuation, but I will simply point out that there is definite underlying strength in Linkedin’s user adoption curve at the moment. In fact, it has reached all-time U.S. audience highs in 7 of the past 12 months and has grown 58 overall percent in the past year. As Linkedin continues its evolution from being an online business rolodex to a more social and interactive content experience, it will be interesting to see if its rapid visitor growth is accompanied by a surge in user engagement.

Twitter.com also had a particularly strong month in May with 27 million U.S. visitors, representing an increase of 13 percent in the past year. (Note: while much of Twitter’s usage occurs away from the Twitter.com site, past Comscore research has indicated that approximately 85-90% of Twitter users visit the website each month). Twitter’s success in May can likely be attributed in part to the exceptionally buzzworthy news story of Osama Bin Laden’s death, as well as ongoing discussion of the Royal Wedding.

Also not to be overlooked is social blogging site Tumblr, which has made some noise this year and become a serious player in the social networking category. The site has grown an impressive 166% in the past year, reaching 10.7 million visitors in May, its first month ever surpassing the 10 million visitor mark. Tumblr is clearly experiencing a viral adoption curve right now and may be nearing that point at which other social media sites have reached that critical mass threshold that propels it to more widespread adoption. It still has a ways to go before we can mention it in the same breath as Linkedin or Twitter, but it just might get there if it maintains its current trajectory.

So even as we look back at about 8 years of social networking mania here in the U.S., we can see there are still a lot of new wrinkles emerging in the storyline as established players reach new highs (or lows) and emerging players raise their profile. Only time will eventually tell which stories are still yet to be told…