The ISBN stands for International Standard Book Number, and currently contains 13 numbers. This number identifies your book and registers your book with a particular publisher. In addition, the correct registration of your ISBN will list your book as being “in-stock” at Ingram and Baker and Taylor, two large book distributors, even if your book is an e-book or print-on-demand book.

Places like Amazon and Smashwords will give you a ISBN for free. Other places will also give your book its ISBN at no charge. However, whoever issues your ISBN is your publisher of record, and there are reasons why you might want to choose who assigns your ISBN:

• If someone besides yourself acquires the ISBN assigned to your book, you are not self-published. The entity who assigns and registers your ISBN is your publisher. In the case of large companies, your book may be published alongside mountains of other works you would rather not have your book associated with.
• The price for single ISBN numbers in the United States today is $125. The price for a block of ten is about $350; the price for a block of a hundred is about $550. For many writers, this is a barrier to entry. In addition, your book needs a separate ISBN for each format, so you need one for Kindle, one for iTunes, one for a .pdf version, one for hardcover, one for softcover, one for audiobook, one for multimedia book, and so on. The price can be prohibitive for novice authors, because buying one at a time is expensive, and buying a block of ten may be beyond your budget (and if you intend to write only one book, what do you do with the other ISBNs?).

Because we buy ISBNs in bulk, we are able to offer you a single ISBN at a substantial discount. If you want to test the waters inexpensively, you can do so with an e-book; begin with one format, and use the sales from that format to finance the next format.