Mobile ad startup MoPub aims to put a fresh spin on mobile ads today with the launch of MoPub Marketplace, a real-time bidding service for mobile ads that lets publishers take full control over the ads on their apps.

Founded by former Google and AdMob employees, MoPub launched late last year with the goal of letting mobile app publishers serve ads directly rather than go through an ad network. Now with MoPub Marketplace, the startup is attempting to demystify the process of choosing and managing ads.

The Marketplace brings together publishers and ad buyers in a real-time trading platform. Think of it as a “virtual trading floor for mobile ads,” as the company describes it. The Marketplace allows ad buyers to better target audiences, and it also opens up new sources of revenue to publishers.

“Until today, publishers have had to operate their mobile ads through a black box: blindly trusting ad networks, without knowing which ads are effective and with no control over the type of ads consumers receive,” MoPub CEO and co-founder Jim Payne said in a statement today. “This matters considerably to the top tier publishers we are working with who are concerned with brand protection as well as ad performance.”

MoPub calls itself an “ad server”, not an ad network. In addition to the Marketplace, MoPub also offers direct sold ads (something more suited for bigger publishers), and ad network mediation (letting publishers juggle multiple ad networks using its technology).

The company says that the Marketplace offers “unprecedented control” for mobile ads. You can view the performance of all of your ads (see the dashboard above), set price floors and frequency caps, and even hide the name of your app, which can help to preserve your brand. The service also lets you easily block ads with one click (meant to help you avoid ads that could hurt your brand), and create block lists, which can include competitors and specific advertisers.

MoPub currently has over 650 publishers on board with its existing service. The company is going head-to-head with mobile advertising heavyweights like InMobi, which  recently raised over $200 million, and Millennial Media.

San Francisco-based MoPub has raised over $6.5 million from Accell Partners and Harrison Metal Capital.