Advertising is a paid, one-way communication through a medium in which the sponsor is identified and the message is controlled by the sponsor. Variations include publicity, public relations, etc.. Every major medium is used to deliver these messages, including: television, radio, movies, magazines, newspapers, video games, the Internet (see Internet advertising), and billboards. Advertising is often placed by an advertising agency on behalf of a company.
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 public address systems. Advertisements are usually placed anywhere an audience can easily and/or frequently access visuals and/or audio.
Advertising clients are predominantly, but not exclusively, profit-generating corporations seeking to increase demand for their products or services. Some organizations which frequently spend large sums of money on advertising but do not strictly sell a product or service to the general public include: political parties, interest groups, religion-supporting organizations, and militaries looking for new recruits. Additionally, some non-profit organizations are not typical advertising clients and rely upon free channels, such as public service announcements.
The advertising industry is large and growing. In the United States alone in 2005, spending on advertising reached $144.32 billion, reported
