Lady Gaga
Lady Gaga

As the first Twitter user ever to reach 20 million followers, Lady Gaga is no stranger to social media. Last year, the pop star took it one step further when she and Google chairman Eric Schmidt contributed to an initial $1 million investment in The Backplane, a community platform that yielded Gaga's social networking site Little Monsters.

@FortuneMagazine - Last updated March 29 2012: 1:47 PM ET
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