Radio is the biggest medium. There are more radio set in circulation than TV sets or daily newspapers. From 6AM to 6PM Radio is the first news source. More people get their news during the day from the radio than TV and newspapers combined. Radio build frequency.
Radio is the most cost effective medium.
Advertisers all over America report building business with Radio Advertising. Radios audience keeps growing. More listeners to respond to your ads. Radio reaches Receptive Listeners. Heavy Radio listeners are more willing to try new products than heavy Tv viewers or heavy newspaper readers.