Here's how I see eBooks on iOS devices.
With music - the iPod is ubiquitous for playing music. And if you don't have an Apple device - it's easy enough to get music onto whatever you have
However eBooks from the iBookstore can't be read on anything other than iOS devices. And there's a LOT more competition for eReaders/tablets than there are for music players.
A book on Amazon - even though it's proprietary can be read on any computer, android, iOS and I assume Windows 8 phone/tablet/device
A book from the iBookstore can ONLY be read on an iOS device.
For this reason - Apple isn't likely to "own" this space.
With music - the iPod is ubiquitous for playing music. And if you don't have an Apple device - it's easy enough to get music onto whatever you have
However eBooks from the iBookstore can't be read on anything other than iOS devices. And there's a LOT more competition for eReaders/tablets than there are for music players.
A book on Amazon - even though it's proprietary can be read on any computer, android, iOS and I assume Windows 8 phone/tablet/device
A book from the iBookstore can ONLY be read on an iOS device.
For this reason - Apple isn't likely to "own" this space.