[dragonwriter]

Contract-derived interests rely on the parties to the contract having underlying property interests that can be exchanged via contact, so, no, contracts don't get you it off dealing with property law, since they depend on it.

[belorn]

Currently, contract law do not dictate if it can be exchanged. E-books might or might not be transferable, and its currently up to the e-book seller to decide if that is the case. Property law, as far as e-books are property, do not come into effect unless e-book is made to be governed by property rules.

Could you explain how property law comes into effect in this case? If it does not, why could patents not be treated in the exact same and equal way.

[dragonwriter]

Property law is what provides the rights that are then sold by contract; in the case of ebooks, the rights specifically originate in copyright law. That's why the eBook seller had the choice of what rights (including whether or not they are transferable) to include in the contracts by which it transfers some rights to consumers.