If an iPod and any other old mp3 player can play all the same songs and play them just as well, what makes an iPod infinitely more popular and profitable than any other player?
iPods are more popular and more profitable because of everything besides the content you can place on them. That is, iPods rule not because of the central reason you buy one (playing your favorite songs) but because of everything else.
This is a big deal for broadcasters to understand. Especially as we move to a world where your music can be duplicated – song for song – by an endless parade of competitors, each more novel (and with better PR) than the next.
You can be the iPod in that world, but not if you reduce your utility to the song library and the order in which the titles therein are played.
It's everything except our music that will make us the most popular place to hear music in the future.