[RWeaver]

Unless you think of a dynamic ad market as an efficient market signals system critical to the economy.

Ie get the most interesting market messages to the right people, while not bothering the rest.

Not that I do anything related to advertising, but when done intelligently it can actually be a pretty important.

[Wilya]

The "while not bothering the rest" part effectively doesn't work, though. People who will never buy anything from an ad in their lives still get ads served to them, because the cost of serving ads is roughly zero.

The facts that ads are paid per click and not per impression creates more ad impressions, not more efficient ones.

[rlanday]

I think there are a lot of people who claim to not be influenced by advertising but actually are. Just because you’re not clicking on ads doesn’t mean they’re not succeeding at influencing your behavior:

http://www.nielsen.com/us/en/newswire/2009/is-the-ad-biz-thr...