Compare and contrast:
While there's much to quibble with in the second article*, it's still an interesting exercise in perspective, and looking outside a niche.
*For instance, just because a phone ships with MP3 playing capacity, doesn't mean it'll be used, whereas an MP3 player is going to be used to play audio files, by default. Thus, the comparison isn't like-with-like. There may be 90m musicphones out there, but how many are being used for music?