For me, the fantastic thing about the first iPod was immediate access to any track, combined with shuffle play. It changed the experience of listening to music. It was like my entire collection had a single, superfluid interface. And the thing FELT great.
Even if you credit marketing with bringing this to people's attention, it's a mistake to think that marketing closes the deal. That credit goes to the experience, which was as imaginative, compelling, and well-designed as the object itself. As the (very) old ad agency joke goes "Nothing destroys a bad product faster than good advertising." Clearly that's not happening here.
I will never understand people ignore the product itself while insisting success is "just" marketing (as though this were an invariably witless task). Usually this is followed by "to people who are idiots." Perhaps you just don't appreciate things that are carefully considered and well made. There are people like this, and there always have been. And they suck. Or as Shakespeare put it "you blocks, you stones, you worse than senseless things."
But nobody bought Nomad, and everyone bought an iPod. Why? Because Apple told people to buy an iPod, and people tend to do what they're told.