Those are the same goals, at least in a capitalistic free market. The theory is that consumers will go towards products which are better (meaning, less obnoxious), and therefore the obnoxious websites will either die off or give up the banners to conform to the market.

Naturally, as you can see, free markets are purely theoretical. In practice, up and leaving a website you're using is almost never easy, and isn't even a choice you can make often.