The really interesting question is, how did that happen?
A lot of Apple's enormous and well-deserved success could be attributed to iTunes, I think. The iPod was a huge success, pulling people to use and start to get locked into the iTunes universe. Around the time of the release of the iPhone, iTunes was the benchmark and it was the massive differentiator of what made the iPhone the device to have (it's all very curious now. I keep no music on my device, using online sources like Rdio). The iPhone begat the iPad, etc.
A lot of Apple's enormous and well-deserved success could be attributed to iTunes, I think. The iPod was a huge success, pulling people to use and start to get locked into the iTunes universe. Around the time of the release of the iPhone, iTunes was the benchmark and it was the massive differentiator of what made the iPhone the device to have (it's all very curious now. I keep no music on my device, using online sources like Rdio). The iPhone begat the iPad, etc.