Inside AdWords blog announced that Google will be improving the algorithm for evaluating landing page quality. The new algorithm will effect AdSense publishers in a big way. According to the blog:
"In the next few days, we will be making two changes to how AdWords evaluates landing page quality. First, we'll begin incorporating landing page quality into the Quality Score for your contextually-targeted ads, using the same evaluation process as we do for ads showing on Google.com and the search network. Advertisers who may be providing a poor experience on their site will notice that their traffic across the content network decreases as a result of this change. Second, we're improving our algorithm for evaluating landing page quality and incorporating landing page content retrieved by the AdWords system."
According to Google these changes will affect only a small portion of advertisers. There will be an 'increase in minimum bids for Google.com and the search network and/or a decrease in traffic across the content network' for those providing a low quality user experience.