In addition to discounts, promotions and coupons, you can also offer gift certificates to your customers. Gift certificates are basically redeemable for credit in the store. When a customer purchases one, you use the Gift Certificate Manager to generate a code which is then given to the customer (either by email or on a printed certificate). It can then be used by them or the recipient upon placing an order. Please note that if you use the Shift4 payment gateway, you can offer their gift cards instead and process them like credit cards