This is an explanation from Google's "Chief Economist" of how the ad auction works when you advertise in AdWords. Essentially an auction happens at every moment when there's an opportunity for displaying an ad. The part I hadn't caught before was how the Quality Score plays a part. The Quality Score depends on the ad's past performance, but also on the content of the landing page that it points to. If Google's algorithms decide that it is relevant to the content of the ad, the score goes up. The better the quality score, the less you pay for ads. [ Articles / adwords | 3 Jul 2009 @ 20:15 | 1563 comments | PermaLink ] More >