anyone here stuff keywords to control ads?

[sunshine]

Let me begin by saying my sites are guides to obscure eastern european cities, so naturally air fare and cheap flights are totally relevant.
Googles fuzzy logic didn't see it that way, and instead ran ads on studying the language of this particular country, student organized trips, and other low paying categories.

I knew my viewers were interested in airfare, they constantly write emails asking me where I buy tickets, so i stuffed a few tiny keywords like "air fare, cheap flights, cheap tickets", on the bottom of the home page. Google now runs those ads.

My income on that site has been much higher for months and to my surprise remains so even after the travel season has ended.

Is google against this even though the keywords were stuffed to help ad relevance beyond what the bot is capable of?