Publishing Perspectives has an article looking at the current problematic nature of the ISBN system when it comes to e-books. The article is a good summary of the situation as it now stands, summing up the ongoing debate between whether to give each format of an e-book its own separate ISBN, or assign one ISBN to the entire book.
Publishers tend to favor the single ISBN approach, while booksellers and wholesalers want one for each format. Perhaps not surprisingly—publishers are the ones who would have to pay for the ISBNs, after all, whereas retailers would get the most benefit from having separate unique identifiers for sales tracking. There is even a suggestion to issue separate ISBNs by region to make tracking regional sales easier.
The article says that “the International ISBN Agency and standards body EDItEUR hope to develop a web service whereby supply chain partners can easily request and receive format-level ISBNs from publishers”. In September, Bowkers announced it would be cutting the prices of ISBNs considerably.
One unrelated interesting thing I found in the article was this:
HarperCollins UK gives one ISBN to its e-books in epub format, which is the only format it sells. Says Graham Bell, head of publishing systems at HCUK: “We sell an epub to Amazon, and they sell it on to the consumer in a lightly modified version. Because Amazon sells the Kindle version exclusively, there’s no need for a different ISBN. We know that an Amazon sale is a Kindle sale.” The same will be true of iBooks sold by Apple.
A “lightly modified EPUB”? Really? Given that the Kindle is not compatible with EPUB, that must be some “modification”.
In a separate editorial/comment thread starter, Edward Nawotka asks whether separate ISBNs are really needed. It will be interesting to see the answers.
It seems to me that an appropriate solution for digital publishing (whether the book is printed from that digital copy or sold as an e-book) would be a Digital Object Identifier (DOI) standard with an addition for edition. Far be it for me to change existing standards, but a 2nd level suffix for edition might work well for pricing schemes (“free edition suffixes”).
ISBN worked well for print, but maybe it’s time for something new. The hard part is finding the interim solution — so that booklisters’ software and databases don’t need to be changed overnight.
“A “lightly modified EPUB”? Really? Given that the Kindle is not compatible with EPUB, that must be some “modification”.”
I doubt much modification is needed to change epub to azw, and it doesn’t take much modification to break compatibility. Also, don’t forget that epub is a consumer format AND a source format.
Cosidering both ePub and azw are baisically variation of HTML underneath the coversion should be relatively easy to do.