Obviously, Waterstone's got to Ottakers in the nick of time! They were so doooomed before the real deal came along.
('Dead' Stock is books that cannot be returned to the publisher. A bookseller can return books to the publisher between 3 and 12 months of the last invoice for that item. Anything past this is 'Dead', it eats up valuable shelf space that could be used for books that shift units and it also eats up your cashflow - generally the idea in bookselling is to sell the book a few times before you have to pay for the first copy. This, generally, never really happens.
Still, 5%!!!! I've worked in shops where the dead stock was pushing 40%! I could go into our nearest Waterstone's at Trafalgar Square and within the hour point out 10% worth of dead stock and 40% of overstocking. How bloody cheeky are they.
Actually, this kind of hubris makes me jolly annoyed indeed. A curse on all their houses)