Facebook's exponential growth made the social networking site the fourth largest website in the world last month, with a total of 340 million unique visitors, according to research company ComScore. Facebook receives 37 million more unique visitors than the Wikimedia Foundation sites, but trails behind Google's 844 million, Microsoft's 691 million and Yahoo's 581 million.
In the past year, it has grown 157 percent, gaining 208 million visitors. It long ago passed its rival MySpace on a global basis, way back in April, 2008. Since then, it has passing even bigger sites on its way up. In the chart above, the blue line is Facebook. It passed Amazon back in August, 2008. eBay fell by the wayside in January, 2009. It surged past AOL sometime in February, 2009, and just last month it finally passed the Wikimedia Foundation sites (which includes Wikipedia).