How are loyalty cards used in shops?

Answer 1

Loyalty cards are used to serve loyalty card program in which customers are given discounts, offers, deals, points on shopping merchandise and coupons.

So, customer can use the loyalty cards to purchase new products on discount, get something for free or redeem his coupon.

Loyalty cards help both the party simultaneously i.e. due to Loyalty Cards retailer is able to track customers buying habit and customers data. And the customers are getting discounts. So, it's a win-win situation for both.