One hundred million. It's a hard number to wrap one's head around. If we were to stack the average bill from nearly any currency in a 100,000,000 column, it would quite nearly reach the altitude that commercial jets fly in.
Without exception, Pocket Edition has outsold PC Edition in every country in the world. With few exceptions, Console Edition (for every platform considered) has surpassed PC as well. Neat!
This brings up an interesting question: what platform do you play Minecraft on the most, and why?