So if suddenly all tracking stopped, advertisers would just stop spending money on advertising? That doesn't seem right... advertisers published ads before tracking was a thing, they would still do it if tracking becomes impossible.
The very idea that a user needs to be tracked from site to site and a profile built around his/her web activity is dystopian and depressing.
With respect to eg brand advertising: even if you get past an inability to measure impact, once you break most of the ad infra, ad buyers simply aren't going to negotiate / buy with small sites. It's not worth their time or money. Small here is probably less than millions of uniques per day.
With respect to direct response advertising, you've mostly lost the ability to track a conversion. So it becomes pointless.
The advertising before extensive tracking was a different time: way way less money, way fewer ads, way less ad blindness amongst viewers, way way way fewer publishers, etc.
Will some advertising persist? Absolutely. eg the branded / source trackable referral codes that podcast advertising uses. But there will be an enormous falloff in dollars pointed at publishers.
And to be clear, I'm not a fan of 3rd party tracking. But we should be deliberate before we end the ad-supported internet.
I could see bigger sites expending a lot of energy trying to bring the tracking and inference in-house, and even federating these efforts, creating a kind of soft-paywall that requires you to "pay" by validating an email address or some other stable identity marker in exchange for temporary access to content, so they can watch what you browse and build a shared model of you that they can feed back into the ad networks. I could see the NYT continuing to manipulate and fine-tune its headlines and graphics, trying to sort its visitors into cohorts based on what appeals to them to squeeze every last cent out of a pageview.
At the same time, so much content discovery and consumption happens in the belly of the beast (Facebook, Google, Youtube) that most ads will continue to be targeted based on the considerable information those websites have about you, regardless of what browsers do or what happens to third-party tracker networks.
And banning extensive user tracking doesn’t mean “ending the ad supported internet”, that’s sensationalist to the max!
To suggest that ending tracking would mean that sites have to individually negotiate ads with individual websites isn’t true either - ad networks have and will always be a thing, regardless of the ability to track.
Second, if this will truly cause a drop in advertising spend.... then that money will be spent somewhere else, which might boost a different industry.
I don't think this would really change advertising spend, though... it would just change the type of advertising and how it is tracked/paid for.
Advertisers still want to get their ads in front of people, and the amount of content to advertising demand wouldn't change.
In fact, I think a change to content based advertising will help with content quality. With user based advertising, an advertiser doesn't care if the valuable person is viewing good content or not. Content creators just need to attract the valuable eyeballs, and can use as much click bait and useless content as possible to get them.
With content based advertising, the advertiser will spend on quality content, because that is the only metric they have to try to reach quality users.