According to Bowker, it is okay to keep the same ISBN when you make minor changes like fixing typos. You only need a new ISBN when you make *substantive* changes, like adding a new chapter or changing the ending of the book.
From the Bowker FAQ
(For the purposes of this discussion, a "reprint" is effectively the same as uploading new ebook content.)
As for changing the cover, it comes back to managing customer expectations...
From the Bowker FAQ:
When in doubt, go to the source:
https://www.myidentifiers.com/help/isbn
Thanks for that link, DRM.
As I said earlier, though, revisions do usually result in a new edition. So I don't think we're disagreeing with one another here. To clarify, it's very unusual for a book to have corrections made without a new edition being involved, although minor corrections such as typos are sometimes made when new print-runs are instigated.
The real issue here, I think, is that there's such a difference between how trade publishing and self publishing work. In trade publishing, the emphasis is on making the book a finished product before it's published; whereas I've seen many self publishers make frequent revisions based on their readers' input. It seems to me that it's not uncommon for some self publishers to treat their first readers almost as editors, and to expect those early readers to report problems which the publishers then clean up*.
As to the first, I'll try to explain, although it is just an opinion or my observation. When we had just physical books they came with ISBNs.
Print editions still make up the bulk of books sold, and they still come with ISBNs.
If the format was changed then it had a separate number. Self-publishers did or didn't use them, but less people self-published then than now because of cost so I don't think the publishing industry really noticed.
Trade publishing is a completely separate business to self publishing (there's far more crossover between vanity publishing and self publishing--witness the number of vanity publishers which have now rebranded themselves as self publishing service providers). It's not that trade publishing didn't notice that self publishers were doing things differently: it's that it didn't affect trade publishers one bit, so why would they notice or care?
How self publishers use or don't use ISBNs did have implications for book sellers, however, on the rare occasions that self-published print editions made it onto their shelves. Their lack of ISBNs, and their unreliable use of them, made it harder for bookshops to process orders for those books and track their stock of them, and added to booksellers' general reluctance to stock those books.
This doesn't imply that, as you suggested,
how unprepared the publishing industry was for this. Obviously they never expected self-publishing to take off the way it did.
It just shows that many self publishers didn't and still don't understand the benefits of an ISBN, or how they should really be used.
People still self-publish some with ISBN numbers some without that part is the same, but now there are so many more doing it, because cost is little to none, all because of e-books. So since some use ISBNs for each format, some don't and talk about reusing them it just seem the waters have gotten muddy over it.
I agree that more people are misusing ISBNs now, and there are more people not using them at all. But that doesn't mean that how they should be used has changed, nor does it imply that trade publishing is somehow at fault, as you suggested.
And it seems to me (and I could be wrong) the publishing industry did not lead the way on e-books, but followed after. I just thought had they lead the way maybe it would have set a precedent on the correct way to use the ISBNs on various ebook formats. Was my thinking anyway. Am I making more sense?
Trade publishing did lead the way in e-publishing, as Medievalist has already explained. Trade publishers tend to use ISBNs correctly. They always have, because so much of their accounting systems depend on them.
As to the other, I should have said, " Although it is
not necessarily needed, I think I would still prefer my own ISBN on each (mobi, ePub) on my ebooks. Sorry
Thanks for the clarification.
* I find this approach really difficult to understand. In my view, we should nurture and cosset our readers, in the hope that they'll then be more likely to buy more books; and we should never lose sight of the fact that it's their money which drives all of our publishing efforts. If we treat them as editors who have to pay us for the privilege (I can never spell that) of cleaning up our books we're going to alienate them, which is not a good thing.