One method of price discrimination for firms is the use of coupons and rebates. Firms are basically allowing consumers to self-identify their respective price elasticities of demand for a product. Describe the last time you used a coupon or a rebate, and another time where you knew a coupon might be available and yet chose to not bother with it. Make sure to explain how the opportunity cost of your time and effort played a part in the choice you made.