Entrepreneur: Rand Fishkin, 29

Funding: $1.1 million from Ignition Partners and Curious Office

Having served as designated Web expert for his mother's Seattle-area advertising firm, Rand Fishkin knew the ins and outs of search engine optimization—essentially, how to help a site stand out in search results. First, he blogged on the subject. That led to consulting, which in turn spawned SEOmoz, which offers free and fee-based tools for businesses looking to stand out in search results. Launched in 2007, its 5,000 paying clients include real estate site Zillow, Village Voice Media, and four divisions of Microsoft—plus another 135,000 using the free tools.

Lessons learned: "The buck stops here," says Fishkin, adding that he took a substantial salary cut at the onset of the economic downturn.