If you are a Google Adsense publisher, you probably have already received Google’s email about Third Party Ads:
We’re happy to announce that the Google content network now
accepts display ads served from qualified third-party vendors.
During this initial release, only ads in English are eligible,
although we look forward to offering more options in the future.
By accepting third-party ads, we can attract a greater variety of
advertising on the Google content network, which we believe will
result over time in increased revenue for publishers and more
relevant advertising for end users.
What this means is that Google has opened its content network and can now accept ads from qualified third party vendors. Some of the identified third party tracking vendors include DoubleClick DFA, Mediaplex/ValueClick, Eyeblaster, EyeWonder, Interpolls, Pointroll, Unicast, Dynamic Logic/Safecount, Factor TG, IAG, and InsightExpress.
Many large, top-brand advertisers use third parties to create and manage their ad campaigns. By accepting ads from these third parties, the Google ad inventory is expected to increase — ultimately translating to more ad earnings for Adsense publishers.