Note that from 28th December 2011, it will
no longer be possible to access any ebooks bought through the previous WHSmith ebook store.
This doesn't mean that people will immediately lose access to their books. Downloaded ebooks should work on any device registered to your Adobe ID.
But it does mean you'll have to be very careful in your back-ups, and make sure that you don't lose access to your Adobe ID.
WH Smith are advising all customers to re-download their ebooks, to make sure they have a copy before 28th December 2011.
In addition, it means you won't have access to any updates made to the books you've bought, if those updates are released after 28th December 2011.
I bought
Unfinished Tales and
The Silmarillion through WH Smith. Bother.