There are many different types of online coupons such as discounts, free shipping, first-time customer coupons, and free giveaways.
In finance, with respect to bonds, a coupon is the interest rate that the issuer pays to the bond holders.
In manufacturing and materials science, a coupon is a small piece of material used for testing or further processing, compare billet.
"Football pools" promoters in the United Kingdom also use this name when referring to the paper grids which gamblers fill in to bet on the results of football (soccer) fixtures. On these, players will mark a number of crosses (x) against individual game listings to indicate which they believe will end as a draw, or tied match. Rewards for correct forecasting can be of very high monetary value.
Online retailers often refer to Internet coupons as "coupon codes," "promotional codes," "promotion codes," "discount codes," "key codes," "promo codes," "shopping codes," "voucher codes" or "source codes." Internet coupons typically provide for reduced cost or free shipping, a specific dollar or percentage discount, or some other offer to encourage consumers to purchase specific products or to purchase from specific retailers. Although online coupon sites have been around for a while, they are now making a come-back due to the weak economy.
Manufacturers and retailers also consider Internet coupons to be those that resemble traditional offline coupons, but can be printed from a user's computer and redeemed in-store. Some of these Internet coupons employ print-controls and other security technologies in order to mitigate coupon fraud risks unique to online channels (postings to "freebie" sites, unlimited prints, etc.).
Printable coupons have been both a blessing to consumers and a curse for retailers. For several years, printable coupon fraud was rampant because the technology was behind the concept and users were savvy about saving coupons to PDF files. Saving coupon files to PDF is considered fraudulent use of coupons and goes against the manufacturer's intention behind issuing the coupon. These days, printable coupons are easier and safer to print, but that doesn't ease the rules for some retailers who've opted not to accept them anymore.
Another movement is to see local coupons brought to users online. This is giving small local businesses better online exposure to communities across the world.