No, that won't do it. The ad network won't know who you are because it can only see what you've done on that site. With no way to carry an identifier between different domains, the value of the ad network is destroyed and ad techniques like retargeting (when you put something in your cart on one site and see a coupon for it on another) are impossible.

> The ad network won't know who you are

You (and the ad networks) seem to be under the mistaken impression that you have some sort of a right to that information. You don't, and acting like a stalker should be treated as such.

As another poster said, you target your ads to the content it is being published next to. Seriously, can you not see the damage you're doing by pushing "surveillance as a business" model? If your hopefully-profitable idea relies on a key aspect basically every single dystopian story ever told (fiction and non-fiction), maybe that's a sign you should find another way?

The alternative, if you want to keep pushing stupid gimmicks like that "coupon" thing, it will just push more and more people into treating the advertising industry (and later, internet commerce in general) as the enemy.

>> No, that won't do it. The ad network won't know who you are because it can only see what you've done on that site. With no way to carry an identifier between different domains, the value of the ad network is destroyed and ad techniques like retargeting (when you put something in your cart on one site and see a coupon for it on another) are impossible.

That sounds awesome.

The ad could just be targeted to the content it's next to. If I'm reading about surfing, try and sell me a surfboard.

OK so the Safari 'No Ads' button effectively becomes a 'Do Not Track' button. Users still see ads, just not targeted at them specifically.

This is a very effective response by publishers because many users who would have enabled 'No Ads' simply will not bother to enable 'Do Not Track'

> because it can only see what you've done on that site

I'm not sure what the problem is - all they need is to ask the publisher to set the cookie for them. Then it's a first party cookie that is relayed on the back end to the ad network, who gets all the same information from it that they used to get.

I go to Site A and get a cookie. Now I got to Site B and since it's on a new domain I have no cookies set and am basically a brand new visitor, so I get another cookie. Even if both those cookies are being relayed to some backend, how can it ever tell that I'm the same person on Site A as Site B?

Then they'll have to start implementing workarounds. The EFF made an interesting tool [1] a few years ago to show how easily you can be tracked from your browser configuration and installed plugins/fonts/etc. There might be more advanced tricks nowadays.

[1] https://panopticlick.eff.org/

Mobile is exactly where you don't want to rely on this kind of fingerprinting. Especially on iOS, it's a platform with only one rendering engine and no plugins.

Here's what it managed to get from my iPhone 6[1]. This would be the same 'fingerprint' as virtually every iPhone 6 user in the UK.

[1] http://i.imgur.com/IkccCei.jpg

The ad network is able to serve content natively through the domain of both A and B. That means they can send back a beacon pixel to Site B from Site A's domain, which will let them link the two ids. They only need to do it one time to link up the ids for a pair of domains.

Said beacon pixel is what will be blocked by blocking the network domain.

cookies are domain specific. If you could get and set cookies from any domain you wanted you would basically be God.