We need a good feedback mechanism. Of the major forms of advertising (TV, radio, web, mobile), which allow you to respond to the ads? None so far. But I don't think it'll be that way for long.
Facebook? Much as we all love to hate them, they do in fact offer the ability to remove ads from both the right hand side and the feed. I have no idea if this matters, but it is an attempt to allow feedback (at a relatively imprecise level).