Compared to ten years ago, the audio industry has changed significantly. Ten years ago featured the Compact Disc as its main medium. The stereo systems were black boxes that had no 'curves'. Nowadays, we see a good audio device as one that is compact, durable, good looking and affordable. An obvious example of this would be the MPEG 3 Layer File (.MP3). Contrasting the .WAV file, it is extremely small, yet keeps its high quality.
As soon as they became popular, we saw the development of the MP3 players, along with music sharing programs like KAZAA and the notorious Napster. I don't know about everyone else, but MP3 Players are quite expensive, and can only hold so much.