That's exactly how most brick-and-mortar transactions work. Entering the store in and of itself isn't value I have to tender value in exchange for. If I want a gallon of milk, that IS value, but the only value I must offer in exchange is the posted price of the milk, in money, not personal information.
Using traditional commerce as an analogy is a mistake for these people. The stores trying to hop onto the spy-on-your-customer bandwagon with loyalty cards are the ones who are out of order, not the customer who expects his purchase to be anonymous as it historically has been. And -- there are plenty of stores that don't insult the dignity and intelligence of their customer base in that way, including the bane of any liberal, Wal*Mart, and a store that I suspect is disproportionately staffed and patronized by liberals, Trader Joes.
Right. I go into a store and buy a soda and pay cash - they wont know me from Adam. They definitely do not get to follow me everywhere I go afterwards
So I guess you never give them your grocery card to save the extra money on the purchase?