So, simply bundling all formats and selling in, say, a ZIP file, wouldn’t resolve the problem because it goes beyond just sales.

Bowker has always claimed that each format needs a separate ISBN, but the actual marketplace has been going in the opposite direction. Amazon, for example, has now entirely stopped using them for Kindle books. This is not to say that Amazon-style proprietary solutions are the answer.

The price of ISBNs has been rising much faster than inflation for many years. I doubt the current pricing model would survive a letter from a class-action lawyer identifying monopoly-pricing issues.

The old 10-digit ISBNs (9 significant digits and a check digit) all have an equivalent ISBN-13 that is the original 9 significant digits with 978 prefixed and a new check digit at the end.

So you might be able to persuade the EAN authority to allocate a new prefix for eBook EANs, but then you’d also need to set up a numbering authority for ebooks to allocated numbers to publishers, essentially duplicating the ISBN authorities, although perhaps using just one global authority rather than lots of country specific ones.

It might be possible. But the new ebook EAN-13s are unlikely work with existing systems expecting ISBN-13s. (I would expect many of the systems that accept ISBNs will reject any that don’t begin 978 or 979.)

I think that small (or large) publishers worried about the cost of ISBNs for multiple formats of ebooks would be better off abandoning the practice of selling each format separately, and instead selling customers a bundle of all available formats. Then only one ISBN is required per ebook, not per format.

And if DRM costs involved with each format make this uneconomic, perhaps they’d also be better off not wasting their money on DRM systems that only annoy their paying customers, not the people who download books for nothing.

This may not be something that Steve Jordan or others think they need, and that is their choice not to use it. Myself, I have used a web-based UUID generator on the few public domain books that I have converted to ebooks. But this method certainly would not suit the purposes of many others.

I haven’t looked into the intricacies of ISBN or EAN-13, but I do have a question. Is there a particular numeric sequence, or some other easy way to distinguish an ISBN from an EAN-13? If so, then it should be fairly easy to make a software change to allow the use of one data field for both, while still separating them out for other processing.

As has been pointed out, e-books are not physical matter, so most of the constraints and requirements of physical sales do not apply. Most of the rationale for ISBNs is directly related to physical sales… and although they could be applied to electronic sales, they are not necessarily the best tools for them.

Physical sales also tend to be more centralized and interconnected, again requiring tools like ISBNs to keep things straight. In today’s more distributed web-based sales world, this is not a constraint. For example: I sell my e-books from my own website; I could arrange for ads or referrers from other sites; and only I need to worry about tracking my sales. And with a fairly simple system in place, a Paypal storefront and a delivery script, I can do exactly that right now, without needing ISBNs, or worrying about whether anyone else can read my figures.

Common identifier usage, based on centralized sales of physical content models, would mostly benefit traditional sellers using traditional methods to sell non-traditional products. Fine for them… but they are not everybody, and their needs do not need to be imposed on those who are looking forward.

I am more in favor of developing new selling tools and methods that better fit the less centralized, less constrained Digital era of the future, not using jury-rigged tools and methods from the Physical era of the past.