I think there still is a big opportunity for ad companies that try to actually show stuff the user might interested in. Let me explain.<p>Let's say you are an amateur astronomer, like me. You have subscribed to a paper magazine about astronomy, like me. If, again, you are like me, then you also read the magazine for the ads in it. Ads showing new telescopes, ads talking about astronomy expeditions, ads for the astronomy club. It is advertisement on the one hand, but still relevant information for my hobby. The companies that buy ads for a longer period burn their brand into my brain, in the "relevant" section of it.<p>Now let's talk about how this would be on the web. When I visit a site about astronomy, I can expect the ads to show: flight offers for the business trip I recently googled. SAS software because I recently did a certification with them and visited their website. Amazon ads showing me business books I recently searched there. But what they often do not show: relevant, juicy astronomy related ads. And when they do, the ad is gone the next time I refresh the page replaced by something else. The ads on the web are most often totally out of context. They might be shown to you because of your recorded behavior before, but still they are totally irrelevant.<p>Probably running an ad network with great ads would be much more manual work than running the next past-behavior based network that tries to mine user data for new ideas. But at least for special interest sites, it could be a gold mine.