Facebook is now the third largest website in the world, taking the No. 3 spot from Yahoo!. According to comScore. Facebook estimated 648 million unique visitors from across the globe in Nov'10, compared to Yahoo!'s 630 million.
In Oct the two sites were dead even with 633 million worldwide unique visitors each.
The two Web properties are Microsoft with 869 million, and Google 970 million worldwide visitors, when you look at all of their sites collectively.
In the U.S., Facebook is at No. 4 in terms of total monthly visitors (with 152 million).