A collection of discount coupons grouped together on a single medium forms what is known as a coupon train. These coupons, grouped within the same train, are usually for products that are not in competition. The advantage of a coupon train lies in the possibility of sharing the costs among several advertisers. There are professionals who specialize in creating and distributing these coupon trains. These trains can be distributed through media such as newspapers, postal mail, or even by hand delivery.