Jose Antonio Vargas: Anatomy (and Meaning) of the "Did You Know?" Video Series (VIDEOS, PHOTOS): "With more than 300 million users, Facebook is like a country of its own. As Mashable reported earlier this month, Facebook grew by 25 million users from Sept. 15 to Nov. 6. If you do the math, as Mashable's Ben Parr did, that's a daily growth rate of 471,698 users. 'That's a small city joining Facebook every single day,' Parr wrote."