Google take into account when working out the Keyword Quality Score & Ad Rank the CTR of the Ad: So you set up a brand new Ad Group with 2 new Ads. How long does Google wait, before taking into account the Ads CTR before deciding on the Keyword Quality Score change & Ad Rank change? Or is it case of 'only google knows this'? I'm sure I read on here that it's after 2 weeks that the CTR is assessed and the Ad Rank & Keyword Quality Score is changed accordingly?
"Quality scores are updated based on how quickly Google can gather statistically significant data sets to calculate a new quality score. This can happen numerous times a day for high volume keywords and phrases whereas lower volume terms may have quality score updates applied a few times a week. The ad rank quality score is updated in real time and is based on historical data." http://www.ppcdiscussions.com/2008/03/adwords-quality-score-faq.html (question+answer #11)