Facebook just keeps getting bigger: The social network that started 2009 with 150 million members signed up No. 200 million in April, and by September it had amassed 300 million an average growth rate this year of about 550,000 new members a day. And with that growth came new demographics: 71% of Facebook users now live outside the U.S., and many of them are older than the site's original college-age demographic. But even more surprising than Facebook's exponential popularity was the announcement that, for the first time ever, the company was making money. Not too shabby for a start-up run by a 25-year-old Harvard dropout.