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, and mobile devices such as cell phones. Since coupons are typically distributed to targeted markets or regions while excluding others they are a form of price discrimination visit for full article http://www.geria.net/2010/08/02/marketing-your-website-through-coupons/