I was under the false impression they have hash that was created by playing the ad and got that back to confirm the ad ran somehow.

I'm not familiar with tbh because the idea of working on ad software and SEO seem like the most boring possibly ethically dubious jobs.

Tied to your IP, which makes it collection of personal information. Meaning you need to consent to it and they are not allowed to do it unless it's strictly necessary in order to deliver the service, bill you and so on.

They can choose not to provide the service unless you pay.

They can also choose not to provide the service to unregistered users and give out free daily watches as a part of their marketing campaign. Then you enter a simple contract by opening an account and agreeing to their terms.

Terms which can include data collection, but it has to be possible to opt-out from it without losing access to the service.

Just a handful of (binary or more) attributes such as that one are enough to tell apart a user from thousands of others.