By Sunshine K. Mugrabi

A year ago, the only wiki most people had heard of was Wikipedia—the online user-created encyclopedia managed by the nonprofit Wikimedia Foundation.

But over the past six months or so, such sites have been popping up all over the Internet. Many are built using tools provided by two recently funded startups: PB Wiki and WetPaint.

PB Wiki, based in San Bruno, California, received a $2-million cash infusion Wednesday from Mohr Davidow Ventures to pursue its strategy of selling wiki-building tools to non-techies.

San Bruno, California

Its competitor, Seattle-based WetPaint, which is also aiming at the newbie market, garnered $9.5 million in January in a second round of funding led by Accel Partners, a VC firm that has backed such Web 2.0 startups as Facebook and Glam.

So, are VCs onto something, or is this another Web 2.0 bandwagon? Wikis, in essence, are web sites that anyone can add to or edit. What gives them potential as revenue-generating vehicles is that communities actively participate in their creation.

Such an audience could represent the ultimate in targeted advertising. “A very focused wiki could be quite valuable to marketers,” said analyst Greg Sterling of Sterling Market Intelligence. So far, however, wikis have yet to grow to the level that would interest most marketing firms.

Carving a Wiki Niche

PB Wiki, founded in 2005, is a scrappy startup with a total of $2.3 million in funding. It has six employees, including its founder, David Weekly, and several engineers.

The company has carved out a niche among educators and small business people, said Mr. Weekly. Its basic tool is free to users, but upgrades require subscriptions. Mr. Weekly said he’s growing revenues at 20 percent a month.

WetPaint is a free, advertising-supported wiki service. Most of its sites are created by groups of enthusiasts around a particular topic—say, dogs or Britney Spears. Its CEO, Ben Elowitz, said there are more than 200,000 WetPaint wikis, with new ones being added daily.

Several other wiki-building sites are out there, but most—such as Twiki and Socialtext—aim squarely at a business audience. Recently, Google acquired its own wiki-building site, JotSpot—a sign that big Internet companies recognize the power of such tools.

Wikipedia founder Jimmy Wales is also getting in on the for-profit wiki game with his latest venture, Wikia. The question now is, will users stick around long enough to make these ventures pay?