As of
December 31, 2012, there are 1.06 billion monthly active users on facebook and
680 million mobile users. On an average, 3.2 billion likes and comments are
posted every day on Facebook. 72% of web audience is on Facebook. And why not!
There are so many activities going on facebook from wall posts, sharing images,
videos, writing comments and liking posts, etc. In fact, Facebook started using
Hadoop in mid-2009 and was one of the initial users of Hadoop.