Does Google allow you to advertise a site totally unrelated to the keyword you bid for? For those who came late, or rather just recently, Adsense Arbitrage is when somebody clicks on a .05 Dollar keyword ad to come to your site to exit by clicking a 2-3 dollar ad. Cool? So imagine, that you bought adwords for say, cooking, and it ends up on a site which is about lawyers selling litigation service againts Restaurants for Pink slipped Cook. Hmmm.. Unrelated to who is searching for a recipe maybe, but to google algorithm, totally related. Also you may give description related to the keyword, but the real website offers something totally different. How does google take care of that? Just a Question.
Maybe you can use unrelated keywords but your CTR will be very low. I think that Google Adwords has nothing to do with algorithm.
No, they do not allow this. How, when they check I do not know but I do know it is not allowd. Not to say you cannot work a system like you suggest, but you can't do it quite the way you describe. In fact there was a thread quite awhile ago about doing this sort of thing. Simply you look for related but lower paying keywords so you can get your ad approved, and then the content targets higher paying keywords. You will need to create a page that generaters some serious EPM to make it work though. A few people in that old thread were claiming that they had some keyword/content combinations that consistently made money. Part of that was watching CPC rates in and out carefuly since they can change over time. Come to think if it I had a landing page that I was driving traffic to with PPC and it had AdSense on it. The ROI on wasn't breaking even but it wasn't terrible either. I think this was because the difference between what I was bidding and the top rate was considerably different.