The Google-certified ad network capability is powered by the DoubleClick Ad Exchange that we announced today. Certified ad networks are Ad Exchange participants who have gone through an additional certification process in order to be able to to bid for your ad space through AdSense. We call this feature "yield management", because it offers you the most revenue for each ad that shows on your site in real time, regardless of whether it's Google or another certified party who can offer you the highest bid.
You don't need to change any of your account settings to start allowing these ads to compete. Also, you can continue to use the Ad Review Center to control which certified ad networks can appear on your site.
Opening AdSense to certified Ad Exchange participants means that more advertisers will be able to bid on your ad space. We believe this will ultimately help you earn more revenue for your sites.
Posted by Sean Harvey, Business Product Manager, and Scott Spencer, Group Product Manager