No. 6

Matthew Staver/Bloomberg News

No. 6

Marc Andreessen, 38
Investor

No. of Angel Investments: 53
Companies funded (a sampling): Business Insider, Digg, LinkedIn, Qik, Scribd, Twitter

You can thank Marc Andreessen for popularizing the Web. As a student at the University of Illinois Urbana-Champaign, he helped create Mosaic, the first widely-used Web browser. He went on to co-found Mosaic Communications, which eventually became Netscape Communications, maker of the Netscape Navigator. The rest, as the saying goes, is history—or more accurately, what turned out to be a course change for the tech industry. These days Andreessen concentrates on investing. He is a general partner in Andreessen Horowitz, a $300-million venture fund formed last July with Ben Horowitz.

If he could have invested in any tech company in its early days, Andreessen would have picked Intel, "since under Andy Grove [it] was the best run company we've yet seen in the Valley," he wrote in an e-mail. "But for returns, you can't beat Google!"

Andreessen noted that less money is required to start a company today, particularly "certain categories of companies such as those based on software IP [intellectual property]. Initial funding rounds of $500,000 to $1 million are far more common now than they were 10 or 15 years ago, because far more companies can be started, and can build an initial product, with that much money now." Several factors contribute to this trend: outsourcing, Web services, more powerful software, industry-standard hardware, cheaper bandwidth, open source software, and "super-precise and capital efficient advertising on sites like Google and Facebook," according to Andreessen.