[m0llusk]

The product that lifted Apple out of mediocrity and into the public eye was the iPod. The iPod, especially in its initial release, had a feature list that was explicitly derived from the failings of competing products. The idea was to take and dominate the mobile music player market. All of the biggest power moves Steve Jobs made were about eating someone else's lunch.

[filesystem]

This implies that the MP3 market was already sufficiently large or saturated by the time the iPod came on the scene, which is false. The MP3 market at the time was mostly an intersection of tech-savvy individuals and musicians. Everyone else was still using portable CD players or walkmans.

[eloeffler]

At the time, portable CD/MD players and walkmans were competing products to the iPod. mp3 players weren't a separate market. There were even portable CD players that could read mp3s off a CD.

[cupofpython]

anecdotally, I had CD player first then I moved to iPod and downloaded limewire

[giantrobot]

The iPod's initial release did correct some misfeatures of competitors but it was not a mass market success. It took Apple until the third generation iPod to hit mass market success. The first two generations of iPod only had FireWire connectivity, available on every Mac but very few PCs. With the third generation iPod USB 2.0 capability was added giving it compatibility with a huge portion of PCs.

Sales skyrocketed after the addition of USB support. After the addition of USB when the iPod took off it didn't outright kill the competition. It just sold so well and expanded the market so much that the PMP market became the iPod market and also-rans.

The iPod had a lot of competitors but no real competition in terms of sales. The PMP that killed the iPod mini (that was selling like gangbusters) was the iPod nano. I'd argue that the iPod was the opposite of a zero sum product because it expanded the PMP market far beyond its size at the iPod's inception.

[yobbo]

The big difference was iTunes/store integration, which would have been impossible for any of the smaller companies.