Sheryl Sandberg is part of latest crop of billionaires joining the Giving Pledge; she's leaning in along with Kinko's founder Paul Orfalea.

"The latest class of signatories to the Giving Pledge – the billionaires’ commitment, started by Warren Buffett and Bill and Melinda Gates, to give away half of their fortune during their life or upon their death – will be announced later this morning. Among the seven new “Pledgers”: Facebook COO Sheryl Sandberg, the second self-made female tech billionaire (after Meg Whitman) who now becomes the second woman (after Spanx’s Sara Blakely) to pledge to give away the majority of a fortune she made entirely herself." -- Randall Lane, Forbes.com

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