In marketing, a coupon is a ticket or document that can be exchanged 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, magazines, newspapers, the Internet, directly from the retailer, and mobile devices such as cell phones. Since only price conscious consumers are likely to spend the time to claim the savings, coupons function as a form of price discrimination, enabling retailers to offer a lower price only to those consumers who would otherwise go elsewhere. In addition, coupons can also be targeted selectively to regional markets in which price competition is great.