Campaigns: Basic coupon code system

Description

Allows marketers to assign a promotion code to a discount, and only users that supply the promotion code to qualify for the discount. You can override the promotion code processing in a site implementation to do custom validation and tracking. See also: http://world.episerver.com/documentation/Items/Developers-Guide/EPiServer-Commerce/9/Marketing/coupons/

Using promotion codes
A promotion code is an additional criterion that you can apply to any discount. A typical use case is: shoppers who enter promotion code CouponABC during checkout receive an additional 10% off the order.
To apply a promotion code to a discount, create it the same way that you create any discount. In addition, in the discount screen's Promotion codes field, enter a unique promotion code. If you create such a discount, it is activated as long as the shopper enters the promotion code and the other discount criteria are satisfied (for example, the discount is active, date is within the active date range, eligible items are selected, and so on).
_