Here is an infographic on the growth of Social Media in 2011. Still growing and I suppose this is due to more and more of a person’s life being integrated online and more people who never thought they would have a social media account giving in to the pressure. After all, people are measured by how many friends they have. We are all in the race to be popular.
There are some discrepancies with Twitter from reading other blogs (mainly Digitalbuzz Blog) so do take this with a pinch of salt. But the rest seems accurate.