The add-free segment of the internet does indeed sound like a niche market. I wonder if quality of results could be drastically improved by just penalizing domains that contain a lot of referral links and ads. I remember the days when it felt like you could learn anything by searching the web a bit until you found some suitable content to read. Now it's like sifting through reams of affiliate spam that I have to at least skim before I can tell that it's low quality garbage.