[nightmiles]

I always struggle with this. On the one hand, advertising used iPhones after searching for "used iPhone" is the most relevant of relevant advertising. It presents information that's actually interesting and useful. If we are sitting around acknowledging that we're hitching our wagons to ad revenue, this is what everybody wants.

On the other hand, those ads might be burying a search result that offers a better, cheaper, or more reputable place to buy that used iPhone. This is a win for the advertiser since the game is influencing behavior, but that consumer might kick themselves for missing a better alternative because the ads were in the way. This reality subverts the ideal mission of an Internet search engine: to return the most relevant and interesting result first. It's not as if Google hasn't been working hard since its inception to improve this, too.

Disclosure: I work for a company that makes (almost) all of its money from ad sales.