08/28/2013 03:09 pm ET Updated Oct 28, 2013

In Photos: The World's Most Powerful Female Entrepreneurs

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Sara Blakely, Founder SPANX

At 29 Blakely invested her entire life savings, $5,000, trying to come up with something flattering to wear under her white slacks. Six months later the one-time Disney World ride greeter and door-to-door fax machine salesperson found her new line of shaping underwear named one of Oprah Winfrey's Favorite Things. Since then Blakely has taken Spanx from a one-product wonder sold out of her Atlanta apartment to a powerhouse with $250 million in annual revenues and net profit margins estimated at 20%.

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