This is so on point. The big problem w/the various UUID proposals is it assumes publishers can (or even should, which is a larger question) push users to use their standard email to sign up to websites and then consent to have that email spread all over the ad tech ecosystem. https://twitter.com/jarroddicker/status/1349398045889277959

Where users can't control consent, this is basically hijacking their email for some very specific purposes outside the context they'd expect, which is problematic at the very least (I mean don't you hate it when your physical mail address gets sent to marketers?)...

But it is also a proposal that sits firmly in the past, when users who wanted to sign up for things had to use their single personal email to do so. Let's put aside that pretty much everyone has minimum a work and personal email that fractures them in the proposed UUID systems

The real threat to the entire concept is the fact that Sign in with Apple is going to be the future of sign in for everyone. Which means when your users sign up, it will be with a different email for every service, and you'll have no way to tell otherwise. https://support.apple.com/en-us/HT210425 

Scrambling emails this way is relatively inexpensive and is going to be a very marketable feature. Privacy marketing is real and if anything has been made clear in the past year it should be this:

When it comes to consumers--privacy *sells*.

Google's WebID proposal includes support for essentially an open standard that would allow anyone to easily hide their email via login vendors. Even if they didn't, emails are cheap and easy to scale up, there's no technical reason for any provider not to offer "Hide my email"

There are huge business incentives for login systems to provide "Hide my email" as a feature. Hiding the users email locks sites into continuing to offer support.

If you are a vendor that also has an ad biz *coughgoogle* then you have an extra incentive to supply the "Hide my Email" feature keep people in your walled garden and unavailable to any other ad tech vendors, now buyers have to come through you.

There are consumer, marketing & business incentives all outside the ethical interests in privacy to make the future of the web one where users are able to use a different email to sign in to every website & the technology exists to do so without any impact to how they use the web

The future where everyone has infinite burner emails and uses them to log in automatically without even thinking, or perhaps even being aware of it, is clearly ahead of us. And it is a future that completely sinks every UUID proposal.

Asking users to log in, blocking access with reg or paywalls, & adding additional friction to get to actually reading the thing users want to read... that is going to challenge publishers and make it difficult to build trust. This pitch only gets harder https://twitter.com/jarroddicker/status/1349400502233141249

That doesn't even get into the fact that the UUID proposals may recreate all the data leakage concerns that kneecap publishers in the programmatic world and hurt the promising future that can come of building up strong audiences and context.

There's a lot of interesting technical work being done, & it is always worthwhile to experiment, but at some point we should consider just how much is rearranging deck chairs on the Titanic & consider how it can work towards more privacy-respecting alternatives like Trust Tokens.

And this doesn't even get into all the *really interesting* stuff that can come from email scrambling as standard. As an individual, I've found such huge benefits from generating up tons of different emails that sit in front of my inbox for different purposes, outside of privacy.

It's exciting to see ever more ad tech development happen in the open instead of in dark black boxes. Here's hoping we all try and use that opportunity to steer towards calm waters.

I'm also excited to see how this fundamental challenge can refine publishers' pitch to their users to interact, sign up, and subscribe. Access and ad personalization are only two pieces of the whole, and ones we're going to have to dig into even deeper than before.

Yup, this is another big danger, that using emails this way risks salting the earth we want to grow on. https://twitter.com/robinberjon/status/1349415736263979009?s=19