Ah I see the 45 minutes was misleading. I didn't mean it because otherwise you could just use a mobile CD player (are these still being made?). Just in general I wouldn't see a point in having a MP3 player, unless I went the same extremely boring route every day for long stretches of time (and not by bicycle).

I suppose the majority of people are commuters, so maybe commuting alone is sufficient to explains the high market penetration of iPods.