Actually, usually the creator of the application showing the ads does in fact sign a contract with the ad publisher. They get money in exchange for clicks; if

Actually, usually the creator of the application showing the ads does in fact sign a contract with the ad publisher. They get money in exchange for clicks; if they are obtaining those clicks through subterfuge or dark patterns, they stand at a minimum to not receive their ad revenue, and if it is egregious and done with intent, then there's no reason that it wouldn't be considered fraud. Measuring and enforcing click fraud is probably the single biggest technical challenge involved in being an ad publisher. EDIT: For example, Google AdMob: https://support.google.com/admob/answer/48182 https://support.google.com/admob/answer/48182