I just wrote this post on my blog about the question whether AdSense is looking at traffic for ad targeting or not: AdSense looking at traffic for ad targeting What do you all think? Does AdSense look at the traffic of your seperate pages to determine what ads to serve on the whole site?
They definately do something like that because I've tried taking a proxy site and changing all of the content to a completely different subject, all of the ad's were still the same as if I didn't change anything at all.