Facebook reached the one trillion pageviews mark in June according to data complied by DoubleClick, an ad network that is also a subsidiary of Google. This makes Facebook the most visited website on the internet. In addition to this, Facebook received about 870 million unique visitors in June 2011, which is about 120 million more than the number of its registered users. One reason for this is because Facebook pages show up in search results and are visible, if only partially, to non users.
Facebook hits the trillion, Zuck's gotta smile
From this data, it looks like the social network gets about 1,150 pageviews per visitor. This includes clicking on other people's profiles, playing games and clicking through photos (each photo counts as one pageview). The website that came next in being most viewed is YouTube. The video sharing site had 790 million unique users in June and 100 million pageviews. Some websites that DoubleClick doesn't release data on is adult websites, Google search and some other sites owned by Google. In the list of top ten most visited websites, Microsoft had the most number of its own sites on the list, including Hotmail and Windows Live sites. Bing came in at number 11.