In 1922 AT&T believed that, based on its patent agreements, it had the exclusive right in the U.S. for commercial radio broadcasting. Although it had sold radio transmitters through its Western Electric subsidiary to a variety of firms, such as department stores, AT&T thought that most of these companies would soon find that running their own radio station was too expensive for them to continue for very long. So the telephone company announced that it was building a state-of-the-art facility in New York City -- originally under the experimental call of 2XY, soon becoming WBAY (WFAN today) -- which various companies could lease to make their broadcasts. AT&T soon found that it had been overly optimistic about the demand for its station, as most companies still wanted their own facilities. But by the mid-twenties AT&T's analysis would be proven correct, and the sale of airtime by commercial stations became the standard U.S. practice.
 
Long Lines, March, 1922, pages 6, 10:

OUR  LATEST  JOB

The  Bell  System  Takes  Up  Radio  Telephone  Broadcasting  On  A  Commercial  Basis
Construction of WBAY THERE'S another new job coming to the Long Lines Department. Director Stevenson announces that the business of radio telephone broadcasting is to be engaged in by the Bell System and that the new service is to be handled by this Department.
    The first broadcasting station will be located in the 24-story telephone building at Walker and Lispenard Streets, New York City. Steel towers 100 feet high will be constructed on the roof to support the antennae and the station will be ready to begin operations within a few weeks. If circumstances warrant it, similar stations will be erected at important centers throughout the country. Such additional stations can be connected by our wire system, so it is possible that at some future time the same program can be distributed from any central point simultaneously through any or all of the broadcasting stations.
    We are going into the broadcasting business on a commercial basis for such people as contract for the service. No program of our own will be provided, only the channels through which any one with whom a contract is made can send out his own program. The radio telephone facilities will be available to the public under special contracts in the same manner that our long distance wire facilities are now available to newspapers, banks and other concerns. There have been many requests for such a radio telephone broadcasting service, not only from newspapers and entertainment agencies, but from department stores and a great variety of business houses.
    The Walker Street station will be the first to handle the distribution of news, music and other programs on a commercial basis. It will cover a region from 100 to 150 miles surrounding New York City, although under the most favorable conditions it may be heard for much greater distances. Within the area normally covered there are now probably 35,000 receiving stations. Living in this area are over 11,000,000 people, so that if the service should prove popular it can reasonably be expected that the total of receiving stations will be greatly increased.
    The broadcasting station on the top of our Walker Street building will be equipped with the latest developments of the Bell System, including the use of electrical filters and new methods whereby, as the business grows, several wave lengths can be sent out simultaneously. In this way receiving stations may listen at will to any one of several stations.
    The Bell System has already demonstrated the possibility of talking by wireless, when all atmospheric conditions are favorable, across the continent or even for much greater distances over water. Radio telephone transmission for such long distances is not now dependable, however, and is not to be compared from a standpoint of service or economy with transmission over wires. But for a broadcasting service involving only one-way transmission, where the same message is given simultaneously to many people within reasonable distances of the transmitting station, radio telephony offers a promising field for development.