This is how you look after your customers. I bought the Diablo guide and was dismayed to discover that it was discontinued. Zygor did offer to exchange the guide for the ESO guides, but as I wasn't playing ESO I didn't exchange it. Eventually I just forgot about it, and today saw the announcement for pre-ordering the new Draenor guides. I log in and to my surprise I see that I can exchange the Diablo guide for more offerings than just the ESO guides. Thanks Diablo for my new upgraded Draenor guides. 
THIS is how you look after customers. Well done!
THIS is how you look after customers. Well done!