I saw an interesting way of getting keyword relevant ads on a page without those keywords. Go to the really ugly work-at-home-king dot com web page and look at the 336*280 google ads at the bottom of the page. The one on the left is an iframed, keyword stuffed, "free credit" page, with only the google ad showing thru - you don't see the keyword stuffing unless you hover over the ad and use your mouse wheel to scroll the page - its at work-at-home-king dot com / free-credit-counseling.html I'm thinking this is against TOS.... Yes? No?
It IS against TOS. We've also made such experiments - nice way to bring high-paid ads - you just create a large page full of financial or medical keywords and position iframe so that only ads are visible. In TOS it is called as "content manipulation" and it is against TOS. So... I would not suggest to participate in such way. At least after several hours of such experiments we decided to be honest and stopped doing it.