comScore released the results of a study on the visitation to Facebook.com, which showed the site grew to 26.6 million unique visitors in the U.S. in May 2007, marking an 89% increase versus the same month last year. The dramatic growth comes on the heels of Facebook.com's decision in 9/06 to open up registration to the general public, a change from the previous policy requiring a valid email address from a university or a selected group of secondary schools and businesses.
In the months prior to allowing open registration, Facebook.com's traffic hovered at approximately 14 million visitors per month. However, after Facebook opened its doors to the general public, visitation accelerated to reach a level of 26.6 million visitors in 5/07, up 89% vs. the same month last year and 100% versus 9/06.
Meanwhile, the number of pages of content viewed at Facebook.com in May 2007 increased to 15.8 billion, up 143% versus May 2006 and 121% versus September. Visitors averaged 186 minutes at the site in May 2007, which marked a 35% increase versus the same month last year. Interestingly, engagement levels peaked in 2/07 at 200 minutes per visitor, then leveled off slightly as the influx of new visitors (who tend to begin as lighter users) tempered the average.