That's a different situation IMO. The data is constrained to what I buy from them, and my understanding under the GDPR is that they can't share it with anyone e

That's a different situation IMO. The data is constrained to what I buy from them, and my understanding under the GDPR is that they can't share it with anyone else (at least I never gave permission for that). I can use the store and not flash my membership card if I don't want them tracking a particular purchase. This option doesn't exist with Facebook, you can't opt in and out from click to click. And they share the information with any number of outside parties. Furthermore the charge that Facebook is levying vastly exceeds the value of the information they're forgoing if I pay them.