Types of online discount codes Most coupon codes offer discounts for online purchases, such as a fixed discount, a percentage off the entire purchase, free shipping, or other discount as advertised by the merchant. There are a number of phrases used to mean coupon code, including the following: promotional or promo code, discount code, offer code, gift code, digitalzapvi coupon code, and similar variations. Why Do Merchants Offer Discount Codes? Online merchants offer coupon codes as an incentive to shoppers to purchase from their websites. Many online merchants do not offer the coupon codes directly on the websites you shop from, but instead place the codes within affiliate programs or offer member-only promotional codes in email newsletters or retail blog posts. Some retail stores will include online order coupon codes in print advertising and other forms of business literature.