Try this…
Use the Overture ‘View Bids Tool’
http://www.content.overture.com/d/USm/adcenter/tools/index.jhtml
…and look up a few popular keywords (online casino, online gambling etc.) and check out the sites up near the top that are affiliate sites (as opposed to online casinos)… you can be fairly sure that people paying crazy money per click like that are making pretty serious money.