never said it is not widely used or not effective.
Just saying that it won't matter much if removed from the equation.
I mean, if something makes your life easier, you would be a fool to not use it. but that is like saying not having a ferrari prevents you from driving to the store.
Third party cookies are not simply a matter of making adtech developer's lives easier. Imagine you visit shoes.example and are now on news.example. Both of these sites work with ads.example, and the shoe site would like to show you a shoe ad.
With third party cookies this looks like (simplified MVP form):
1. When you visited shoes.example, it loaded a pixel from ads.example. That pixel automatically sent your ads.example cookie, and put you on a remarketing list.
2. When you visit news.example, it sent an ad request to ads.example, which also automatically sent your ads.example cookie. Now the ad tech vendor knows to include the ad from the shoe site because it recognizes the third-party cookie.
On the other hand, without third-party cookies or any replacement browser APIs, how do these identities get joined? Very occasionally someone will follow a link between a pair of sites, and then you can join first party identities, but you probably don't have a chain of identities that connects a news.example first-party identity to a shoes.example identity.
>On the other hand, without third-party cookies or any replacement browser APIs, how do these identities get joined?
1. When you visit shoes.example, it has an iframe to show an ad from ads.example. This iframe runs some JS to compute a browser fingerprint and then nests an iframe to hxxps://ads.example/?target=shoes.example&client=$fingerprint . The ads.example server records that this fingerprint has visited shoes.example
2. When you visit news.example, it has an iframe to show an ad from ads.example. This iframe runs some JS to compute a browser fingerprint and then nests an iframe to hxxps://ads.example/?target=news.example&client=$fingerprint . The ads.example server recognizes the fingerprint, knows that the client visited shoes.example earlier, and returns a shoes ad.
My parent claimed this was possible to do with link decoration and first party cookie matching, and I'm saying it isn't.
I do agree this is possible to do with fingerprints, though (a) all the browsers are trying to prevent fingerprinting and (b) a reputable ad company would not use fingerprints for targeting. This is my understanding of why Google is putting so much effort into https://github.com/WICG/turtledove
right, if you know how cookies and urls work, all that can happen with zero cookies and some query parameters, like the ones google search surreptitious add on every search result.
cookie synch, It's a freaking industry standard. And you want us to believe google money cow will dry as soon as the effort they are leading goes live?
No, it is not possible to remarket at any meaningful scale with "zero cookies and some query parameters" (though Arnavion's sibling comment is correct that it can be done with fingerprinting). Would you be up for describing how you'd do it in the shoes.example/news.example/ads.example case?
> you want us to believe google money cow will dry as soon as the effort they are leading goes live?
"we are confident that with continued iteration and feedback, privacy-preserving and open-standard mechanisms like the Privacy Sandbox can sustain a healthy, ad-supported web in a way that will render third-party cookies obsolete. Once these approaches have addressed the needs of users, publishers, and advertisers, and we have developed the tools to mitigate workarounds, we plan to phase out support for third-party cookies in Chrome. Our intention is to do this within two years." -- https://blog.chromium.org/2020/01/building-more-private-web-...
hint: the same way attribution happened in the early days.
google sends id abc to shoes.com and id xyz to news.com. both sends those ids back to google's own adserver. presto, google knows you are seeing those two ads.
Just saying that it won't matter much if removed from the equation.
I mean, if something makes your life easier, you would be a fool to not use it. but that is like saying not having a ferrari prevents you from driving to the store.