[Nextgrid]

> whether they clicked one ad and had 4 sessions since, etc.

That's not trivial to do, both from a technical point of view (browsers - rightfully - fight these kinds of tracking attempts) but also legal (GDPR mandates that the customer opts into this kind of tracking but they have no incentive to do so).

[tetsusaiga]

You're right, this is actually a lot harder to recently, with the iOS updates that occurred a year or so ago. It's a space that evolves very quickly.

But this is a good place to point out that, yes - there is nuance to all of this - and I didn't really mean to turn it into a thesis on online advertising (lol) so much as to say:

It's still easy to be more accurate than "Turn it off and see what happens".

Even a semi-sophisticated media buyer is going in with a plan, and some method of measurement.

[m3047]

GDPR doesn't stop me from having ad1.example.com and ad2.example.com landing pages. Aspirationally perhaps, but technically no. I think this is different from fonts.gstatic.com in that it doesn't need to follow people around the internet and it's also not info necessarily going to a third party.