How much of this discount is for tracking, and how much is pure price discrimination? The barrier of carrying a card allows the supermarket to give a discount

How much of this discount is for tracking, and how much is pure price discrimination? The barrier of carrying a card allows the supermarket to give a discount to customers who are motivated by that, without needing to give the same discount to everyone. The value of the tracking is probably irrelevant to how they set the price: it is not that loyalty card discounts have increased since tracking has become more valuable.