Google AdSense network partners can now bid on display advertising positions at top AdSense publisher sites, potentially making top-performing sites more expensive.
Most ecommerce marketers are familiar with Google AdWords, the pay-per-click advertising platform that lets merchants post ads on Google search results pages or network partner sites. Google AdSense is the corresponding service that connects site publishers with AdWords. Specifically, a publisher can register for AdSense and allow Google to place ads on its site. When a merchant buys a keyword, he or she can select from Google's content network, which consists of AdSense publishers.
In an effort to boost revenue for AdSense users (and, presumably, itself), Google has now opened up AdSense to third-party ad networks (agencies or ad serving companies) who will be able to bid for ad positions on the same sites that AdWords users compete for.
AdSense has always been something of an ad auction, with AdWords users competing for space not just on Google, but also on top-content publishers' sites. In the new arrangement, AdWords users will compete with agencies or other ad networks for the same space on publishers' sites.