Spanx: One Woman Success Story - Yahoo! News

Spanx, the not-so-secret, must-have under garment for looking slim and trim, began as a simple idea to conceal pantylines and cellulite, and has since evolved into a billion-dollar multi-product shapewear empire.

From Hollywood's red carpets to local department stores, women everywhere have shared their obsession for Spanx by word-of-mouth, and it has paid off in a big way. The company is estimated to have made almost $250 million in sales last year without spending a penny on advertising, and it is now opening its first stand-alone retail stores this month to offer customers a one-stop shopping experience.

Watch the full story on "Nightline" tonight at 11:35 p.m. ET

Sara Blakely, the inventor and founder of Spanx, said she sometimes still can't believe the widespread popularity.

"It's really hard to digest," she said. "I'll see these celebrities and they look gorgeous and they'll say, 'I love my Spanx' or 'it's because of my Spanx,' and it's hard for me to absorb, like, that's a product I created."

via news.yahoo.com