Pray tell then, what do you do your computing on? I get those prompts for features the manufacturer thinks I might want to use (but don't) on my Android phones, my iPads, the YouTube app, Firefox, and pretty much everywhere else.
Finding relevant ads is a search and recommendation problem, but not all search and recommendations are done for ads. In this case there is a search over popular apps in the store as opposed to an search through an ad inventory.