It is not clear that agency is the issue here. The search ad business is a long-tail business. People who read and comment on HN, who understand how search works, likely are heavy users of search yet contribute little revenue. But hackers are important to Google in other ways because they are the tech trend setters who turned Google into a verb and told their computer-illiterate brethren to just "Google" it. Now just imagine what some of those less literate, who believe in palm reading or tarot cards, would think when faced with a computer that appears to half read one's mind. I mean these are the real gold mines that the ads people are looking for. And once they get comfortable they are not just going to switch based on some technical merits they've never even heard of and the ad market will continue to pay more to those who can deliver more of the "gold mine" type users.