Behavioral targeting firm Revenue Science has landed $24 million in venture capital financing, the fifth round since its founding in 2000 as digiMine, reports the Seattle Post-Intelligencer. Investors include Mayfield, Mohr Davidow Ventures, Integral Capital Partners, and Second Avenue Partners.

Gary Stein, an analyst with Jupiter Research, says about 12 percent of advertisers have used some form of behavioral targeting in their online campaigns, but 45-50 percent of them think it can provide the best returns in online advertising.

The article also describes what behavioral targeting is and who the major players are (Revenue Science, Tacoda and Advertising.com), discusses how Edmonds.com has been using Revenue Science's technology and network, and touches on Tacoda's business.

Behavioral advertising "has a huge potential," said Stein. "But for the potential to be realized, there has to be some education and there has to be understanding among advertisers." The new ad networks are complex because they involve many diverse players cooperating to share ad dollars.

Both Revenue Science and Tacoda are privately held, and each claims to be the biggest player in behavioral targeting. As the market heats up, both could become acquisition targets.