I had query strings from search engines appended to every url, since I thought it a nice service to keep placing this in my on-site search box (for further serching).
But after realizing that the adds where targeted on it, I got scared that it might be in violation with the TOS.
Since every page on my site can be regarded as a search page (it has a search box), however only for local searches. I feel a bit uncertain of where the line goes.
On search result lists, I display other types of ads.
But I wonder about publicly available referral pages? They are indexed by Google OK, and it leads to continous examples of rekursive searches. Often Yahoo searches ends up on the page where i dispaly Google search strings, and vice versa. What do you think about AdSense ads on pages like that?