The average Facebook visitor views 661.8 pages on the social network each month, reports Website monitoring service Royal Pingdom (citing Google AdCounter). Facebook blows away the competition when it comes to this single engagement statistic.
Visitors to Facebook's nearest rival, Hi5, only view an average of 351.2 pages per month. MySpace comes in at 261.8 monthly page views per visitor.
Point is: Not only does Facebook have a huge user-base -- about 350 million people check the site at least once a month -- it has a very engaged user-base. No wonder Facebook ads are finally gaining traction.