Google will rank an AdWords ad based on the maximum CPC, the click through rate (CTR) and the relevancy of the ad text. Google prefers relevant and well-targeted AdWords ads. Google determines ad placement using the value formula: CPC x CTR. The ad is placed higher as the valuation rises. It’s possible for an advertiser to have a high rank position with a low CPC if the CTR makes the value to Google higher than other ads with a higher CPC. Google requires a minimum CTR in order to protect the AdWords program value for its users. Does anyone know how long you can lag in click throughs before you are adversely affected? ~~Corena