Answer:
premiums
Explanation:
Premium offer is a sales promotion technique where a business offers two or more products at a price which is lower than the total costs of all the goods. The method encourages customers to buy more products. With premium offers, customers may also get vouchers, discount coupons, or free merchandise such as tee-shirts, caps, umbrellas with every purchase they make.
Chet has realized that offering a tee-shirt has enticed customers to buy. A free tee-shirt is the incentive that is attracting customers. Premium offers can be used to retain loyal customers and attract new ones.