[electrum]

This was actually the original idea of pay-per-click search ads. GoTo.com was founded on the idea that paid listings would be of higher quality and relevancy, because websites that pay more are likely better sites.

The idea has some merit: you can't spam the search engine with completely irrelevant ads, because users will click them and thus charge the advertiser, but they'll quickly leave the site because it isn't relevant to their search.

Modern pay-per-click (PPC) does yield management and ranks ads based on the click-through-rate (CTR) multiplied by the PPC. So if you create irrelevant ads that no one ever clicks on, they'll stop being shown in favor of more relevant ads with a higher CTR.