Facebook has gained an amazing 24 million users in June, and it now has about 250 million active registered users, but it gets 340 million unique visitors worldwide.

This makes Facebook the fourth largest site in the world, after Google, Microsoft and Yahoo sites. In a single year Facebook has grown 157 percent and got 208 million new visitors.

At this rate, it seems it's only a matter of time before FB outpaces the big three. However, they have between 240 and 500 million more unique visitors than Facebook, so it will take some time to catch up.