06/29/2010 03:24 pm ET Updated Dec 06, 2017

The Most Unexpectedly Profitable Celebrity Businesses

Can't take celebrity prankster Ashton Kutcher seriously? Think again. The actor has built something of a mini-media empire and is one of a handful of celebs who are making millions in their side jobs.

Sure, there have been plenty of failed celebrity businesses and start-ups over the years. Take Britney Spears's failed Manhattan eatery NYLA, for example. Opened in 2002, the restaurant received terrible reviews -- along with a few lawsuits -- and eventually closed, with a $350,000 debt.

But there still are more than a few celebrity businesses from which entrepreneurs could learn a lesson. The secret? Like Ashton, celebrity entrepreneurs who have had success have been expert at seamlessly broadening their personality and artistic vision into the world of consumer brands.

Beloved funnyman Will Ferrell co-founded the wildly successful website Funny or Die with his collaborator Adam McKay. Essentially, web version of Ferrell's sensibility, the site's first video garnered over 70 million page views. Earlier this year, HBO purchased a 10 percent share of the site for $10 million. which is pulling in "tens of millions in revenue."

Hard-partying former Van Halen front man Sammy Hagar is making millions off of his Cabo Wabo tequila brand. Hagar's Cabo Wabo Enterprises, which now boasts the second best-selling tequila in the U.S., has earned about $60 million in revenue per year since 2007. "I don't endorse. I own," Hagar said during a Forbes interview.

In Photos: See 11 celebrity entrepreneurs whose businesses have been a success.

In many cases, these celebrities, like cinephile Robert Deniro, who founded the Tribeca Film Festival, simply pursue what they know best.

Others like the late actor Paul Newman, have blended no-nonsense branding with a an inspiring penchant for philanthropy.

The celebrity entrepreneur business is competitive, but it's necessarily limited to adults. The Olsen twins's company Dualstar Entertainment, has pulled in billions selling videos, clothing and video games, all before Ashley and Mary-Kate could vote. In 2004, the Olsen's turned 18, things got really serious: they bought out their lawyer's minority stake in their own company in order to attain full business control.

See 11 celebrity entrepreneurs who had business success.