President and CEO, Sam's Club
Wal-Mart Stores
2011 rank: 23
Age: 50
Brewer, who began as a scientist at Kimberly-Clark, became CEO of Wal-Mart's warehouse club (fiscal 2012 revenue: $54 billion) in February after a stint as head of Wal-Mart's eastern division. It is a big promotion: She heads one of only three operating segments, and she reports directly to CEO Mike Duke.
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