SAP E-Commerce and Web CRM: The financial gain or advantage that comes from using a coupon when purchasing an item. A coupon can provide a 10% reduction in the amount of the total purchases price, 1 free item, or free shipping, for example. In some cases, a purchaser must meet certain conditions, or requirements, to use a coupon. For example, the user must purchase 10 items or more or must purchase over $100 in items.