Commercial radio stations began broadcasting in the early 1920s, but it would be over a decade before the concept of selling over-the-air advertising would catch on. Many radio stations were established by radio equipment manufacturers and retailers such as RCA and programming was provided to sell the still-patented radio transmitters and receivers (thus effectively establishing a one-time fee model). Programming was financed from the sale of the equipment.
In the early 1920s, commercial radio stations started broadcasting. It took over a decade for selling advertisements over-the-air to become popular. Many radio stations were established by companies like RCA and others who provided programming to sell still-patented radio equipment (thus creating a one-time fee model). Programming was financed from the sale of these devices.