If I recall correctly, Apple didn't really take off until they released a Windows compatible iPod. That singular decision to leap out of the Apple-only ecosystem is what set the stage for the iPhone and the iPad and all other success thereafter. I wonder what world we would be in if Apple had continued to insist on people switching to OSX hardware before enjoying the benefits of the iPod. I suspect that most of the huge market for Windows users would have turned to the Zune, which the few people who actually own them seemed to like. Image a world where the Zune had won the music player wars.