Friday, November 25, 2011
Let's say you have published an ebook (EPUB) and have assigned it an ISBN (eISBN). Then you make it available for e-readers and other devices.
Now suppose there is a POD ("Print On Demand") machine you (or someone who isn't you even) can send it (an ebook) to to make a printable edition (a pbook). Now the ebook is a "float-layout" (or "reflow") format (EPUB in this case), but what the POD machine needs is a "fixed-layout" format (such as PDF). It may be too much to ask at this point to that the fixed-layout PDF can be made totally automatically from the float-layout EPUB: one expects that some editing within a tool (like Adobe InDesign) would be needed to get the book to look right according to the (chosen) page dimensions the POD machine is going to print its output on.
Now would one print a differently assigned ISBN number (one assigned for a hardback or paperback edition) in the pbook (produced by the POD machine) than the eISBN number in the ebook? When you think about it, since you are "just printing out" an existing EPUB ebook with an existing ISBN, it seems strange that a new ISBN would appear in the pbook. Look at it this way: You send your ePub to the POD machine and ask it to print out a 6"x8" version and a 7"x7" version. Would you expect a different ISBN to be printed? Of course not.
2011/12/05: Regardless of the comments in Do I really need a separate ISBN for each e-book format?, I bought a book from Smashwords (one I reviewed): smashwords.com/books/view/94897. I downloaded both the NOOK (epub) and Kindle (mobi) versions. Same ISBN in both NOOK and Kindle versions. That should take care of that confusion.
Another example: Suppose you have an Android tablet running the Kindle app and the Nook app and you download the the EPUB and MOBI versions of the same ebook. Would you expect to see a different ISBN in each reading it on your tablet?
Having a different eISBN on an EPUB and a MOBI is not like hardback and a paperback, it's like having a different ISBN just because there's a different brand of glue used.