The comparison isn't of the hardware product, it's of the operating systems. Developers want to know what the installed base and rate of change for users of each OS is so they know the target market size to make decisions like which OS to develop an app for first. Consumers want to know what other consumers are doing because they don't want to get stuck with a device (like a Blackberry) that the market is abandoning and no one is making third party apps for.