From Niall Kennedy comes a quote from a Walt Mossberg interview with Steve Jobs in the WSJ:
The interesting thing about movies though is that movies are in a very different place than music was. When we introduced the iTunes Music Store there were only two ways to listen to music: One was the radio station and the other was you go out and buy the CD.
Steve, pass around whatever you're smoking because I'd like some. People listen to music at concerts (!!), on television shows & commercials, in movies, on cable music stations, on MTV, in elevators, on hold, on airplanes, in waiting rooms, at friends' houses, at bars & clubs, on my iPod, on old cassette tapes, and most significantly in recent times, people download and listen to tons of music they've downloaded from the Internet. I agree that "movies are in a very different place than music", but I don't think it has much to do with a paucity of ways to listen to music.