Huligan - 1:49 am on Apr 5, 2007 (gmt 0) Huligan
This could be a problem for Google. Some PPA advertisers may only use it as a branding tool. They will set up a conversion that rarely happens and try to gain lots of impressions while paying little for them. I think Google has already thought of this and will set up a quality rating similar to PPC. Poorly performing ad (few conversions) will lose exposure.