Believe me... Google cares... and they'll close your account if they find out you are modifying their code or hiding the texts that identifies the ads as ads.
Don't mess around with Google TOS, because you'll have your accounts closed and chances are you won't have them re-opened again.
Besides, it's not necessary to do that. I can not speak about specific CTRs (against TOS too) but I can tell you that just by making a change in the location and color of the ads, I increased CTR by 5 on one of my sites.
Just be creative and think on people behavior when you plan you page layout.
Maybe the Eye Track III Research can help you figure that out.
http://www.poynterextra.org/eyetrack2004/main.htm
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The fact is that Google has not option but to be ultra strict in their policies. The reason is that Google is dependent on its advertisers for making money. And the advertisers will advertise with them if they make more money by advertising with them!
Thanks for the link to that pretty useful study!
