16. Camille Hart, Executive Assistant to the COO

Hart was Sandberg's assistant at Google for years. She followed Sandberg to Facebook, and then left after less than a year for a job at the San Francisco Giants. She returned to Facebook, where she first supported another executive before reuniting with Sandberg in May 2009.

17. David Ebersman, Chief Financial Officer

Ebersman has been the Chief Financial Officer of Facebook Inc. since September 2009. Mr. Ebersman oversees Facebook's finance, accounting, investor relations and real estate functions. Prior to joining Facebook, he served as Chief Financial Officer of Genentech Inc. He is a fellow in the Henry Crown Fellowship Program and holds an A.B. in Economics and International Relations from Brown University. He is known as the Face of Facebook IPO.

18. Matty de Castro, Sales Executive

Castro is a New York-based sales executive for Facebook. In 2009, he was an account director, but he's clearly risen in the sales ranks since.