I never know the stock price has something to do with Cost Per Click? Isn't it all depend on the advertiser's bid?
it seems since google lost ~100 billion so far this year in stocks they are really tightening the belt, and kicking more publishers off and paying the rest less (since the system is so un-transparent to us they can either take 10% cut or 70% cut to pad their profits, and were still none the wiser)