[lotu]

Because the main site owner then has to spend time coordinating with literally thousands of advertisers to get their ads for their champagnes. They then have a build an maintain an adverser that is hosted in their domain, right now ad servers you buy are hosted in a separate domain.

This also eliminates the possibility of do programatic buying of ads, think Ad Words. Large companies have the money to spend on this, they don't because they don't have to. What you are suggesting would cut every small company out of the advertising space.

[SilasX]

They would just have to agree on a common protocol for the advertiser to pass back what what each bit of ad content looks like. It wouldn't prevent programmatic buying of ads, as you could still forward over the cookies, user data, and other information submitted with request and the advertiser could still condition the ad on this information.

>What you are suggesting would cut every small company out of the advertising space.

I'm confused by your phrasing: I was suggesting a countermeasure, not mandating something that would cut people out of any market. And it would certainly be hard now, because there isn't a common interface for setting up the ad relaying, but that's exactly how thing were in the early web: having an ad provider place ads on your site required a custom[1] solution until there was a common way of doing it.

[1] sorry, "bespoke" is the hip term now...