A newcomer to Fortune's 40 under 40 list decamps from the software giant to the social behemoth. Carolyn Everson's time at MTV may have helped pave the way.

Carolyn Everson

Among the newcomers to Fortune's 40 under 40 list in 2010 was Carolyn Everson (No. 38), a rising star in the advertising world who had just taken over as head of global advertising for Microsoft (MSFT). Today, just nine months after stepping into that role, comes the news that she is moving to Facebook as VP of global sales, a position vacated by Mike Murphy last fall. More