HD radio is limited to a specific range because radio stations, as archaic as they are, are still transmitting from ground towers. You have to purchase satellite radio, usually for a monthly fee, to obtain the more innovative type of radio listening.
Satellite radio can cover the whole continent, while regular radio stations only cover a particular area in a specific part of a state. However, HD radio is free, and it follows the same business model as the standard radio station.
Their income is generated through a great deal of advertising that regularly comes during their broadcasting. Satellite radio, on the other hand, has very few commercials, if any. The main concern with satellite radio is that it drops off. HD radio receives equally digital and analog radio stations.