Apple had complete control of the small form factor harddrives. Noone else could get their hands on them. There were other MP3 players before iPod, but they were either too big, or couldn't hold enough music.
By the time flash storage caught up, it was more about fashion.
In broad strokes, you're pretty spot on, besides not mentioning the simplicity + usability of the software. Apple absolutely made portable music sexy (again) and reaped the benefits all the way to the iPhone juggernaut of today.
Not sure why you got down voted, but here's an up vote.
Apple had complete control of the small form factor harddrives. Noone else could get their hands on them. There were other MP3 players before iPod, but they were either too big, or couldn't hold enough music.
By the time flash storage caught up, it was more about fashion.