Today is the fifth anniversary of the launch of Facebook, so I thought it would be a good opportunity to look at the website’s impact upon the social networking category. Overall, Facebook was the #5 ranked website by total market share of visits in January 2009. One year ago, visits to Facebook represented 15% of the total social networking category while MySpace captured 73%. In January 2009, Facebook’s share doubled to reach 31%, while MySpace’s total share of the category eroded to 57%.

The time spent on Facebook has continued to increase and reached an average visit time of just over 21 minutes in January 2009. The growing audience providing more friends to interact with and features such as live chat, which launched in April 2008 has certainly helped to keep more users spending time on the website (and the sometimes addictive, sometimes annoying status updates). While the average visit time on MySpace is higher, the time being spent on the website has remained consistent as core users remain engaged (despite a shrinking audience).

When compared to 2008, there has been a pronounced shift in the age of the Facebook audience. Visitors aged 18 to 24 represented a 42% share of visits for the 4 weeks ending Jan. 26, 2008, but have now dropped to 24% for the 4 weeks ending Jan. 24, 2009. Now visitors aged 25 to 34 make up the largest share of visits with 27%, with 18 to 24 and 35 to 44 closely following with respective shares of 24% and 23%. In comparison, during the same time frame, 36% of the visits MySpace are from visitors aged 18 to 24.

In addition to age, the household income of the social networking audience is also another hot topic around social networks as advertising becomes a potential revenue stream. With an older audience, it is not surprising that Facebook has a somewhat more affluent audience that may appeal to advertisers when compared to MySpace.

Happy Birthday Facebook – 5 years to reach 5th place behind the likes of Google and Yahoo! is no easy feat.