Over the 1920s and 1930s, CBS produced a series of pamphlets emphasizing the power of broadcasting to reach into the minds of its listeners. One entitled You Do What You’re Told argued that since people tended to obey human voices, radio advertising would be more compelling than existing print forms. Radio, according to the pamphlet, “presents the living voice of authority,” giving it the “supple power to move people and mold them, to enlist them and command them.”

Tim Wu, The Attention Merchants, loc. 343