Google Adwords advertisers will continue to see their Quality Score decrease
(and higher minimum bid requirements as a result) if the value of their landing
pages don't meet
Google's landing page and site quality guidelines. Google started
incorporating advertiser landing page quality into the
Quality Score about six months ago.
From the Google Adwords Blog today:
Landing Page Quality Update
This change to the algorithm will affect a small number of advertisers --
while having a positive impact on the quality of ads that our users see.