22 - Facebook....

Ok.. there are 7.023 billion people on Earth as of 2012. Now, Facebook have 1.15 billion users. Now sure alot of those users will be second accounts and stuff but still that is alot of the Earths population using Facebook.

So...      7.023 / 1.15 = 6.11 is the same as 1 in 6 people on Earth having a Facebook account. Wow. 

Facebook vs (renren == China)

Now China has its own version of Facebook... well that is not technically correct, it is not there version of Facebook, more their equivlant of Facebook called renren, click here to check it out http://renren.com/. It is kind of confusing how many users it has, they announced in a pre-IPO in 2011 that they had 160 million users, but updated that statement then later on in the year to say that they had "a total of 31 million active monthly users", Now this number might have grown hugely in the last year but I can't find more information on it easily. The amount of users that renren has is not my point here, my point is that around 1 in 6 use Facebook, or at least will soon and!

... they are not even allowed into China!