Not the addressed poster, but regarding rewards cards (that I avoid as well) vs ad tracking: You only show your rewards card when buying something in the store

Not the addressed poster, but regarding rewards cards (that I avoid as well) vs ad tracking: You only show your rewards card when buying something in the store the card is valid in/offered by, not when entering a random 3rd party building or when crossing the street. But ad tracking (especially retargeting) spies on you whenever you browse the web without precaution.