Commercial
radio stations make most of their revenue selling "airtime" to advertisers. Of total media expenditures, radio accounts for 6.9%. Radio advertisements or "spots" are available when a business or service provides valuable consideration, usually cash, in exchange for the station airing their spot or mentioning them on air. The United States
Federal Communications Commission (FCC), established under the
Communications Act of 1934, regulates commercial broadcasting, and the laws regarding radio advertisements remain relatively unchanged from the original
Radio Act of 1927, enacted to deal with increasing problems of signal interference as more and more stations sprung up around the country.