Maybe you implicitly agree to their ToS when you enter a partner store? It's a technical detail of creative lawyering. They must have covered the legal aspects and factored in the fines in case they get a slap on the wrist.
I guess it is the same thin line you have between tax evasion and tax optimization and Google has a nearly unlimited budget to try to move this line in their favor.
But it's not like agreeing to a ToS allows you to do illegal things, stalking being one of them. And yes, the definition keeps fitting more and more Google's tracking methods.
I know that I sound dramatic, but all of these kind of things that we have let Google do would be considered HIGHLY illegal if instead of a company it was a single, private individual.
Not dramatic at all, it is stalking, it is unethical but defining illegal is very complicated and up to the elected bodies.
Powerful entities should not be above the law but in practice they are, no point denying that. I'm sure everyone has an explanation according to taste how come double standards can be the normal.
I guess it is the same thin line you have between tax evasion and tax optimization and Google has a nearly unlimited budget to try to move this line in their favor.