OpenX, provider of the popular open source ad server, launched its OpenX Market this week. The OpenX ad server is used by more than 35,000 total publishers who serve ads across more than 150,000 websites. According to the company more than 300 billion ad impressions now run through its software every month.

OpenX Market allows publishers to make their online advertising available to large numbers of buyers and advertisers. Publishers put a floor price on their inventory and can make available whatever online advertising they chose.

The new OpenX Market makes it a viable option for small to mid sized publishers: those who can’t afford a sales resource can access advertisers and ad networks direct, getting the best price for their ad inventory.

This sounds like an ad exchange to me. ReadWriiteWeb’s Sean Ammirati put this to Scott Switzer, CTO and founder of Openx, in a blog post last year:

This line of questioning started with me asking Scott if OpenX ultimately will become an ad exchange. While he wouldn't confirm this, when OpenX talks about "build[ing] efficiency inside the advertising marketplace" it leads me to believe that they will ultimately become an ad network. Scott did point out that they are also trying to be open and integrate with a lot of the traditional networks, such as Right Media - which is certainly a point of differentiation.

While I understand that perspective, according to Scott OpenX is "serv[ing] in the hundreds of billions of ads per month." This is in the same neighborhood as Double Click. And with the recent announcement that OpenX is launching a hosted solution (ultimately giving them even more visibility and becoming closer to publishers) an ad exchange seems inevitable at some point.

With increasing numbers of publishers using OpenX, it looks likely the Ad Exchange model will be developed by the company. OpenX Market will ultimately benefit publishers, advertisers and ad networks, and it is a welcome development.