SiliconBeat

OpenX, an open-source ad-serving platform that competes with Yahoo and Google, announced Tuesday it has raised an additional $10 million in a third round of funding.
The round was lead by DAG Ventures and includes Accel Partners, Index Ventures, Mangrove Capital, First Round Capital and Jon Miller, the former AOL chief who is also chairman of OpenX’s board of directors.
OpenX Chief Executive Tim Cadogan said he was not been formally raising money when the round came together. OpenX, which has about 50 employees and is based in Pasadena, has raised a total of $30.8 million, including $15.5 million that was collected in December 2007. Cadogan said he still has “a good chunk” left of that Series B round.
Cadogan said investors are eager to support the company’s rapid growth. Founded in 1998 as an open-source project to give Web publishers free software for serving ads on their site, OpenX now shows Internet users 300 billion ads a month and sells support and consulting services.
In April, OpenX launched the OpenX Market, which automatically matches Web publishers and advertisers in return for a 15 percent commission. Cadogan said the OpenX Market is simpler and costs less than rivals like Google’s DoubleClick Advertising Exchange and Yahoo’s Right Media Exchange.
Since December, the number of customers using OpenX’s hosted software, which includes a paid premium version, has quadrupled. Cadogan said adoption of OpenX appears to be accelerating despite the faltering economy.
“We have the benefit of building an innovative new business in the middle of a recession,” Cadogan said. A former Yahoo executive who played key roles in search and advertising, Cadogan joined OpenX last year.