you want your own ISBN number or do you want to use one of Amazon's
own ASIN numbers.
Initially I thought I had to have an ISBN number to get my first book created world wide, but that is really not necessary. Also, if you're not careful it can be a very expensive prospect.
If you choose to get an ISBN number, it is important to understand what that means. First, the good part is that if someone wants to look up your exact novel they can go to an ISBN site and search for your exact book. Interesting enough, if you get an ASIN number from Amazon for free there are websites for searching out your ASIN number to find exactly your novel.
If you buy your ISBN directly from Amazon it is expensive. In my case it was $125 for one number.
Sounds great, you now have your ISBN and you can upload your novel as a Mass Market Paperback book, hardcover book and an Ebook with your ISBN, right? Wrong. Your one ISBN is only good for one of those book. Each type of print or ebook layout of the same book could use its own ISBN. At $125 a pop that could turn into a lot of money.
Interesting enough, Amazon offers ISBN's for you to buy from http://www.myidentifiers.com which sells, at this time, a set of 10 ISBN's for $250. This is a much better deal than Amazon's and only requires a little knowledge on your part. But, before you take the plunge to buy your ISBN's, let me point out a few other interesting bits of fact.
If you change from Amazon to another seller like https://www1.ingramspark.com or https://www.nookpress.com/ or a
bunch of other websites. Although your ISBN should work for whomever you are publishing through, it really doesn't. I'm not stating that I fully understand it, but to change your ISBN over to the new company that is offering your books for sale requires some major paperwork. From everything I have heard and researched about this subject. It is simpler to just use a new ISBN for the new company and the same book you're trying to sell.
After making the decision to buy one ISBN for $125 (and not the 10 for $250), I am now questioning how necessary it is to have an ISBN. Why not use each service's free or cheap numbering code they are using like Amazon's ASIN number? As I further prepare my hardback book I will do additional research on this option, but for now I would argue that buying an ISBN number is a waste of time when your self-publishing. It is an extra expense that is not needed if you're wanting people to buy your book directly from Amazon USA, Amazon Europe or the Create Space Estore.