A elevada penetração da rádio

«(...)by 1930, 46% of American households had a radio, and 10 years later that number had grown to more than 80%. By 1970, radio ownership had already reached 98%, nearly the current ownership rate (99%). Of course, one may question the appropriateness of radio ownership as a measure of radio's popularity, for it is entirely possible that a great many radios simply sat unused, collecting dust. However, as seen (...), the increase in ownership is matched by a comparable increase in the number of radio stations» (Paik, 2001: 11)