This is one thing that has intrigued me for a while now. There are many methods that Google use to track us around the web, cookies, toolbar, analytics, signing in etc. Could there be something in the algo that tweaks the results based on the users previous patterns. eg: past successful conversions. Lets say we have 2 advertisers bidding on the same term. Advertiser A has a 8/10 QS Advertiser B has a 4/10 QS Both get the same CTR, have similar average positions & Conversion rates. "This is where I got my brain working in overdrive" User X has a history of many past successful conversions (as recorded by Google) User Y has never recorded a conversion, but does as much online as user X so Google has data, just no conversions. Let the searching begin: User X does a search and Advertiser A's ad is displayed as normal, but not Advertiser B. User Y does the same search, but this time Advertiser B's ad is displayed with Advertiser A's ad not showing. This could mean that the higher the quality score of your keywords, the more likely it is you will receive a higher quality visitor from AdWords. I am not talking about bid prices, just the QS vs traffic quality I know this is all speculation but has anyone seen a correlation between QS of your campaigns and the quality of traffic it brings in?
> Both get the same CTR By definition, this is impossible. If they both had the same CTR, they would have similar QS, unless the term they bid on is irrelevant to them. QS stands for Quality Score. The biggest component of QS is CTR. The higher the CTR, the higher your QS. I believe that your ad will affect both your CTR (that's given) and your conversion. To prove it, I checked the CTR vs conversion rate of some clients. The ROIs were higher for ads with higher click rates, even though the average positions are relatively the same. Conclusion: low CTR (as expressed by a low QS) will usually result in low conversions as well.