I know but my point is even with other options young people are still going to want the "cool" one and that is hands down the iPod. And later on people will stick with the iPod because that is what they know. Apple also has an advantage by having a store on most campuses. Students can charge one to a bursar and pass the student discount on to their parents. Why go for a knockoff when you don't even have to pay for the best one?
I'm old. I'm so old that I heard my first Sony Walkman as an adult. That first model was $400 (if my feeble memory serves). I can buy a nearly identical "walkman" today for about $20.00.
Here's an example -- Suppose someone came out with a player that sold for under $200. The thing is completely ruggedized -- you can accidentally throw it into the washing machine or sit on it and it'll still work. It holds 1,000 songs. And the manufacturer went to Italy and hired a bunch of designers to give it a truly exotic, cutting edge look.
The point being, no manufacturer or product holds a lead position forever.