Answer:
frequency program.
Step-by-step explanation:
Frequency program are reward programes that are based on the promise- Buy X get Y free. It usually requires the customer to make a certain purchase volume to get a reward such as cash, a rebate, or points for another companie's reward program.
Beth makes purchases books with her Venus card and when she gets to five books she gets a coupon for a free book as reward. This is an example of a frequency reward program.