For quite a while, we've been making comparisons between the size of Facebook's user base and the populations of different countries. Now, Facebook may be able to measure up to a few nations in terms of finances, too, with a report claiming the social network generated $800 million in revenue last year. The GDP of somewhere between 14 and 24 countries (depending on whether you want to trust the International Monetary Fund or the CIA Factbook) fell below $800 million in 2009.