A 1991 conversation at a Mexican restaurant led Kate & Andy Spade to ask, "What's missing in designer handbags?" Kate's answer was a simple modern-shaped handbag that launched the iconic fashion brand: Kate Spade.

Richard Branson took a record shop and built it into a label, a bank, an airline, space tourism, and 200 other businesses — all under the name Virgin. But the serial entrepreneur has also had his share of failures.

Computer scientist Tony Hsieh made millions off the dot-com boom. But he didn't make his mark until he built Zappos — a customer service company that "happens to sell shoes." Now Zappos is worth over a billion dollars and known for its completely unorthodox management style.

In 1997, after going for a long run, Seth Goldman was frustrated with the sugar-filled drinks at the corner market. So he brewed up a beverage in his kitchen, and turned it into Honest Tea.

A decade ago, full-time mom Alli Webb noticed a gap in the beauty market: there was nowhere that just focused on blow-drying hair. Now with 70 locations, Drybar is testament to Webb's motto: Focus on one thing and be the best at it.

Zumba began as a mistake: aerobics teacher Beto Perez brought the wrong music to class, then improvised a dance routine to go with it. For his students, it was more fun than work — and it eventually grew into one of the biggest fitness brands in the world.

In 2008, it was nearly impossible to buy a fashionable, affordable pair of glasses online. That simple frustration inspired the idea behind Warby Parker – and disrupted the eyewear industry.

Melissa and Doug Bernstein's first success was a wooden 'fuzzy puzzle' of farm animals. Today, Melissa & Doug makes over 2,000 kinds of toys and serves as an antidote to the rise of digital toys.

In 1973, Yvon Chouinard started Patagonia to make climbing gear he couldn't find elsewhere. Over decades of growth, he has implemented a unique philosophy about business, leadership and profit.

Mark Cuban made millions off of tech startups, then billions off of stocks — and later went on to buy and revive the Dallas Mavericks. He has come to define the persona of the serial entrepreneur.