Google is working on an ad-serving platform for the masses. The so-called Google Ad Manager, currently in private beta, is aimed at small and medium-sized companies, creating a counterpart to DoubleClick’s DART.

The service is going to be free. The underlying purpose of Google Ad Manager is the further spread of AdSense on publisher sites. Just like Google Analytics is supposed to help AdWords clients optimizing their campaigns, Ad Manager is supposed to help AdSense clients to deliver more ads and collect more information about your site.