In an episode of Two and a Half Men, Kutcher reveals some strategically placed stickers – all plugging companies he's involved with.

Hollywood history is full of actors burned by bad investments, but as a tech enthusiast, Ashton Kutcher may be creating a new role for stars with face time to spare: venture capitalist. The actor brings in a reported $6 million a year from his investments.

Kutcher first poked his perfectly formed nose into the V.C. world in 2007, when he became creative director of Ooma, which outfits home phones with Skype-like technology. Then he got in on Foursquare and Flipboard. He bought a stake in Skype several years before Microsoft purchased it and owns a piece of buzzy start-ups Hipmunk, a travel search engine, and ­Airbnb, a short-term home-rental site. In most of these companies, Kutcher’s role is promotional, but in all of them he controls a stake in their upside—which means the possibility of a much bigger payoff than he’d get for a Budweiser ad.

To his credit, Kutcher recognizes that he’s a better promoter than venture capitalist. That’s why he hangs around with “friends who are a lot smarter about those things”: big-time investors Marc Andreessen and Ron Conway and supermarket billionaire Ron Burkle, with whom Kutcher founded a firm called A-Grade Investments.

Kutcher’s V.C. success has meant other stars realized they could invest their money in more than ritzy restaurants. Soon start-ups were getting money from the likes of Leonardo ­DiCaprio (photo-sharing app Mobli), Justin Timberlake (mysterious augmented-reality company Dekko, photo-tagging platform Stipple, and Myspace), Justin Bieber ­(social-gaming developer Sojo Studios). Even MC Hammer, notorious for blowing his fortune in the nineties, has found a home in the Valley. Mr. Burrell announced his new search engine WireDoo last October.

Related:

• Archive: “Cover Story”
• Table of Contents: Feb 6, 2012 issue of New York | Subscribe!