I tested all this for my one page to know what is the actual figure of visitors. I put adsense on page with some content and no link to it then put archin code and started adwords campaign. Painfully saying after 15 days test i have come to know that nobody matches with each other even on daily basis. Interestingly adsense page impressions and awstats are closer (still with 5% plus difference. adwords and analytics are closer. Adwords record more clicks. then adsense then awstats and analytics shown least figure. please comment why there is so much difference?
So AdWords showed more clicks than AdSense? Meaning you paid for more clicks than you got paid for? That's interesting. AWStats is woefully inaccurate . On a real site that gets any traffic, AWStats will show WAY more uniques that there really are. I guess that's why everyone in the Buy/Sell Sites forum uses it
I would disagree with you on this point that AWStats is inaccurate. It is the best trusted source of information you could get. It provides you information based on the server log. Nothing knows better than your server who visited your site. If you think GA provides full info then you are wrong because it does not give any information when the users have javascript disabled.