One of the few countries where Facebook is really struggling is Japan. The Times has a good rundown of the company's struggles there.

The main culprit? Privacy.

The Japanese are avid users of social networking, even mobile social networking, but always with usernames and avatars. Meanwhile Facebook in Japan, like everywhere else, favors real names, real pictures and real connections.

In a survey, 89 percent (!) of Japanese internet users have said they are wary of using their internet names online. Japanese social networks like Mixi and Gree (and, adding insult to injury, American rival Twitter) are huge there but Facebook is barely growing.

Facebook is really sticking to its strategy of emphasizing real names though, which is maybe the best strategy long-term. Facebook does have extensive privacy controls, although it seems the market isn't yet educated on that (heck, social networking users everywhere seem to be uneducated about privacy settings). In India, after struggling for years, Facebook has become dominant thanks to exchange students and other returning travelers who got hooked to the site overseas, and the same thing might happen there.