Google has posted details of a quality score update that will take effect over the next week or so.
http://adwords.blogspot.com/2007/02/quality-score-updates.html
There will be a quality score column in the adwords interface which has been in beta testing for some advertisers to show how Google perceive the quality of a given keyword & ad combination.
Also an update to the quality score algorithm which is concerned with predicting lower quality ads better, dropping rank and increasing the costs on those poor ads and making it easier / less costly to get a new high quality ad into the listings.
最近英文论坛反映说Bid升到$5-$10每点，不知道跟这个有没关系
