Hi, First, I use stat-counter to track visitors. I have noticed that people have exited via Google ads...however the numbers do not match up with the report. I do not think it is double clicking as there are few visitors to my site. On one day there was only one visitor and they clicked on an ad yet there was no report in adsense. Also, when using ad words keyword search and looking a the CPC, if it says X how are you to know what you will get. If word A has a CPC of X and you have an add displaing A what determines if you get X or Less than X. Thanks.
Adsense is like set it and forget it, They may filter out some clicks because of the bad leads, or its a robot following the links out your site. So don't waste your time trying to stalk your clicks, you'll drive yourself crazy
I guess Google has an alogorithm designed to find the quality of the clicks coming from each site..so whaterver you do to track the clicks on your own and the time you invest on tracking them doesnt pay you off...
Best way is link you adsense to your analytics and watch it from there! It will give you a ton of info that you can you use to optimize your site for certain keywords that people are entering the site with and ultimately clicking on links...
i think Google Analytics is best way to see where your visitors are coming from and what do they click on your website. Analytics will provide details of clicks not eligible for payment