Facebook makes the majority of its revenue off of users in the U.S. and Canada, but its user growth in those countries has slowed dramatically.
By the numbers: A Facebook user in the U.S. is 3 times more valuable than a Facebook user in Europe, 10 times more valuable than a Facebook user in the Asia-Pacific region, and 15 times more valuable than a user in the rest of the world. The U.S. is by far the world's most lucrative ad market, worth over $200 billion, per estimates from Zenith, a global media agency. China, where Facebook is blocked, is the second biggest, at $87 billion. Japan is a distant third at $43 billion.