| Advertising is paid and/or sometimes free communication   through a medium in which the sponsor is identified and the message is   controlled. Variations include publicity, public relations, product placement,   sponsorship, underwriting, and sales promotion. Every major medium is used to   deliver these messages, including: television, radio, movies, magazines,   newspapers, the Internet, and billboards. Advertisements can also be seen on the   seats of grocery carts, on the walls of an airport walkway, on the sides of   buses, heard in telephone hold messages and in-store PA systems. Advertisements   are usually placed anywhere an audience can easily and/or frequently access   visuals and/or audio, especially on clothing. |