This post, by Kristen Eckstein, originally appeared on her Ultimate Book Coach site.
An ISBN, International Standard Book Number, has been the standard in the publishing industry for eons to track title listings, multiple editions, book formats, and sales. Knowing this definition alone might make you instantly jump to the conclusion that you do, in fact, need an ISBN for all formats of your book, including the eBook format. But for eBooks the ISBN rule gets confusing, especially with the rise of Amazon’s popular Direct to Kindle program.
The question: Does your eBook (Kindle, Nook, iBook, etc.) need an ISBN? The short answer: It depends. There are several factors involved in applying ISBNs to eBooks, not the least of which is price. According to Bowker, the ISBN agency, every format of every book should have its own unique ISBN for tracking purposes, including multiple eBook formats such as PDF, MOBI, etc. This guarantees publishers are paid the correct amount for book sales, customers know exactly what version of what title they are purchasing, libraries can file eBooks and stock physical books once rather than mistakenly buying the same title twice, and retailers list books correctly in their databases.
However, there is also the price factor to consider. Some eBooks sell only a few dozen copies. In the United States, Bowker (the ISBN agency) charges $250 USD for a block of 10 ISBNs, and you can burn through them in a hurry and never sell enough eBooks to make up the investment for the ISBN. Not to mention the cost of proper eBook formatting, professional cover design and retailers’ required discounts. This may make you re-think applying an ISBN to every eBook you publish. When might your eBook not require an ISBN?
Short answer: If you’re only publishing on Kindle or your own website and nowhere else, Amazon’s Direct to Kindle program has its own internal tracking number assigned to each eBook. Since your eBook is not sold anywhere else, Kindle tracking is all you need and you don’t need to concern yourself with “wasting” an ISBN on that listing. If you publish a lot of Kindle books from interviews, blog content or transcripts, it’s best not to apply ISBNs to those titles.
Which begs the question, when do you want an ISBN assigned to your eBook?