The iPod was already massively popular when the iTunes store was established. And more significantly, the store’s DRM didn’t prevent anyone from loading their iPod with music from other sources, legal or otherwise.

The iPod was even more popular by the time the 2D colored ads were introduced. There’s no denying that Apple’s marketing is next-level, and plays a huge role in their success, but it’s one of many factors. The iPod simply had better UI, a higher storage capacity, and tighter software integration than any other player available at the time.

It was also a great way to put all your downloaded music onto a single device, rather than burning it onto dozens of CDRs.