How did advertising come to support radio economics?

The idea of entertainment supported by advertising came from AT&T's radio station WEAF, which started in 1922 in New Jersey. AT&T charged content providers a fee for the use of its radio stations. The fee was based on how much airtime they used. This evolved into letting manufacturers sponsor programs to advertise their goods, then into advertisers paying to have their ads carried on programs. WEAF broadcast the first commercial. By 1927, radio had attained a different shape. Privately owned stations focused on popular entertainment, heavily tilted toward music, and supported by commercial advertising , a model it retains today. Radio stations and radio networks discovered a way to make a great deal of money selling advertising. Networks arose to supply stations with the most popular entertainment in a way that spread cost across a number of stations. Advertisers saw a way to help create and then reach a mass consumer public, turning people first and foremost into consumers by promoting their goods on the airwaves.