Second, I think a lot of people have good reasons for disliking advertising tech. Beyond a certain point, advertising essentially becomes a zero-sum game. The people who see your ads are only going to spend so much money on stuff, and once you've saturated that, the best you can do is move the money around. It's unlikely that your product is vastly better than what people would otherwise find. Advertising can certainly help get the word out about truly excellent new products, but that use is vastly outweighed by simply trying to switch people from one brand to another mostly equivalent one.
Because of this zero-sum nature of much advertising, it becomes a race to the bottom. In most markets, if competing products A and B both improve an equal amount, everybody benefits. In advertising, if competing ads A and B both become more effective at selling, little changes. The better ad will continue to work better, but the absolute effect will not change much. (In reality, all ads compete against all other ads to an extent for people's money, but the point still holds as long as you look at all of them.) The trouble is that an ad's effectiveness is only loosely tied to its aesthetic value or utility to the viewer. In other markets, when competitors race to improve their products, the result is awesome products. In advertising, the result is ads that are continually larger, louder, brighter, stupider, more difficult to bypass, more insulting, and more annoying. Companies race to one-up each other's ads and the rest of us are just collateral damage in their war.
Ads are intruding on more and more of our lives, including things we pay for. Everybody I know hates sitting through ads after paying $BIGNUM at a movie theater, but somehow the practice has become universal anyway. I suppose it hurts sales less than it boosts revenues. This helps the theater, but it doesn't help me. Tickets didn't get any cheaper when ads went in. For an internet example, take Hulu Plus, which I understand is now showing ads to paid subscribers.
Finally, and perhaps most importantly, ads are probably the single greatest non-government mechanism for invading our privacy today. Ads work better when they're targeted based on personal information, and the result is private companies with vast amounts of information about everybody's browsing habits, held and used in a completely opaque and unaccountable fashion. Ad networks are becoming vast spy networks that just happen to be used for the relatively benign purpose of getting us to buy stuff. And you wonder why we don't like ad technology?