Video featuring products available on SPANX.
Nightline continues from New York City with Terry Moran. Well the same way Wonderbras dominated the 90's the wildly popular Spanx shapewear will likely go down in history as the iconic under-thing of this decade. What started as a simple idea, a fresh take on the old girdle, has now exploded into a billion-dollar empire. And the brains of the operation? You may know her as the youngest woman ever to grace the Forbes billionaire list. Here's ABC's Juju Chang. "Red carpet secrets? Spanx", "Spanx", "Spanx". It's the not-so-secret secret to looking slim and trim. "You have got to wear Spanx". "Spanx". That must-have undergarment "Spanx" celebrities can't stop blabbing about. "Spanx, the best invention". Now word-of-mouth has paid off over 13 years. Spanx now sucks in 250 million dollars in annual sales. With not one penny of advertising. "I think the magnitude of all of it only hits me in moments". The woman behind all those shapely behinds? Sara Blakely, the inventor and founder of Spanx. "It's hard for me to absorb, like, that's a product I created. You know? Like I created that". Spanx is now to shapewear what Kleenex is to tissue. A billion-dollar household name. "What we hear the most from e-mails and phone calls is confidence. I feel confident that I don't have normally. I mean just, it's a really great feeling". Now she's looking to taking that feeling to a one-stop shopping experience. "Come on in ladies, we're open!" Blakely is opening Spanx first-ever stand-alone stores, like this one in King of Prussia, PA. "So, should Victoria's Secret be worried?" "I would say so". In addition to control tops, she's now taking on a new set of curves. Everything from yoga pants, swimsuits, even bras. "And I', wearing one now, it's become one of my favorite products: the "bra-lelujah". "What a great name!" "We had to name it that because it's so comfortable everybody starting going "bra-lelujah". The idea was bring it up to speed and get rid of back fat and have it not dig into their shoulders. So the rest of the bra is made out of panty-hose". "That's amazing". "It's hooks, wires, clasps-free. It's airport friendly". Spanx has expanded to more than 200 products sold in 13 different countries. The simple idea? That undergarments can make or break an outfit has turned Blakely, at 41, into a Forbes cover girl. The world's youngest self-made female billionaire ever. "Where do you put that in your head?" "I think I mostly giggle when I think about it because it reminds me of those backdrops you would choose at the mall with your friends". "Like, I'm the sexiest woman alive!" "Right!" Her mammoth success had humble beginnings in Clearwater, Florida. "I was always trying to figure out ways to make money and do little businesses. I mean my first memory was drawing pictures with my friend on a rainy day and then selling them door to door". But her life's biggest pivot point was traumatic. On a bike ride she witnessed her best friend get hit and killed by a car. In her grief, she turned to self-help tapes. "I memorized all ten tapes of Wayne Dyer's How to be a No-Limit Person. I feel that really changed the trajectory of my life". The tapes helped her cope with failure and rejection: like when she bombed the exam to get into law school. She spent seven years selling fax machines door-to-door. "Sometimes people would be particularly nasty and would rip up my business card in my face. I would just sit in my car and cry and put in some sort of motivational tapes and usually just shift my thinking". And then, she had that "aha" moment that would forever change her life: sparked by a troublesome pair of cream-colored pants. "Every time I put them on, you could see the thong. You could see the panty line, you could see some cellulite on the backs of my thighs. And I cut the feet out of control-top panty hose one time. That's it. My rear looked firm. My cellulite had been smoothed out and I knew that was the idea I had been asking for". So with $5,000 in savings she started cold-calling hosiery mills. "One guy called me after I made the rounds, that I have decided to make your crazy idea. And I found out he ran it by his daughters over dinner. And they said, "dad help this girl make it, it's a good idea". A great idea with a catchy name. "But why Spanx?" "I knew instantly it was right, because my product was all about the butt and nobody forgot it". "What were the runners-up?" "So bad: open-toed Delilahs". "What?" "I know, I know, we would not be sitting here if I'd named it. I know, I know, I realize that". As luck would have it just two months into business Oprah anointed Spanx footless panty hose one of her favorite things of 2000. "I love Spanx, I love Spanx". And the rocket had been ignited. "The orders started coming in all day, all night". From a one-woman business to a shapewear empire in just over a decade. "I fast-forward all these years later and I stand in front of my own store. It's a real emotional moment. Her husband says she's a business titan because she still listens to her intuition. "She didn't go to Harvard Business School, she just trusts her gut. She entered a male dominated space with no business experience and said "I'm gonna go for it". Blakely wants to launch a new generation of female entrepreneurs. For now, through a starter program called Leg-Up. "It's my way to pay the Oprah moment forward. So this is a girl named Lindsay Phillips. She invented a flip-flop called switch-flops". Because the key to Blakely's success is all about taking that light bulb moment and keeping it glowing. "You know if you're in search of your idea, put on your awareness glasses and look at things differently. I mean there are million-dollar ideas everywhere". For Nightline, I'm Juju Chang in New York. What an all-American success story. Thanks to Juju for that. Up next: