If you had to guess how many files people were adding to Dropbox on a daily basis what would you guess? A million? Five million? Nope. It's a freaking billion.

In a speech at Mobile World Congress in Barcelona today, CEO Drew Houston said, in addition to that impressive factlet, that 100 million people are using the cloud storage service across 500 million mobile devices. And by the end of 2013, Dropbox expects to hit 150 million users. Wow. [CNET via SlashGear]