Even if they weren't nearly as ubiquitous as they would become, people absolutely had heard of DAPs before the iPod came out. And, like the iPhone, it took 2 or 3 generations before it was obvious to a lot of people that this was something different--in part because of the ecosystem.

Here for example, is a not very flattering account of the introduction from PC Magazine: https://web.archive.org/web/20011121170057/http:/www.interac...