• by Gavin O'Malley , Staff Writer @mp_gavin, June 6, 2012

Giving it a fighting chance among rival “supply-side” ad platforms, PubMatic just raised a $45 million round led by August Capital, along with existing investors, including Draper Fisher Jurvetson, Nexus Venture Partners, Helion Ventures and Silicon Valley Bank. The company, which helps publishers manage their display ad inventory, continues to face stiff competition from AppNexus and the Rubicon Project, both of which are also heavily funded, and are thought to be considering public offerings. The entire segment, however, is falling out of favor with certain investors.

“After a few years of infatuation, many investors have grown out of love with ad technology companies,” according to AllThingsD’s Peter Kafka. Rather than signaling optimism, meanwhile, Kafka suggests that these companies might have no other choice but to go public. “That’s because Google bought their competitor AdMeld last year, and because the other big display ad companies that would have been logical buyers at one point -- Yahoo, AOL and Microsoft -- don’t seem to be in the market for big display ad tech purchases.” PubMatic doesn’t currently disclose revenue, but CEO Rajeev Goel says the company processes “tens of billions” of ad impressions a month, and that the sites it represents collectively attract 400 million visitors a month.