In marketing, a coupon is a ticket or document that can be redeemed for a financial discount or rebate when purchasing a product. Customarily, coupons are issued by manufacturers of consumer packaged goods or by retailers, to be used in retail stores as a part of sales promotions. They are often widely distributed through mail, coupon envelopes, magazines, newspapers, the Internet (social media, email newsletter), directly from the retailer, and mobile devices such as cell phones.