As an Indie author, there are several choices for bringing your book to the market, both in traditional print (paperback) and the new e-book formats. Globally there are many companies which will allow you to join and sell your books, but few compare with the global powerhouse, Amazon.
Prior to publishing my first book, I researched the internet and reviewed the different ways I could bring my "masterpiece" to market. After much consideration, I chose to use Amazon due to their large client base and the ease with which I could upload my documents and have them converted into an e-book.
For the print version, I chose Createspace.com, which is also an Amazon company. Createspace is a print on demand publisher that is also easy to use and offers assistance and advice on formatting. Createspace allows you to print as few as 1 copy or as many copies as you wish. They also offer expanded distribution meaning you can advertise and sell your print books on numerous online retailers around the globe. When a customer purchases your print book on Amazon, it is printed and shipped through Createspace.
With Createspace, the cost of printing a paperback book is reasonable and the royalty rates are high. I also found using Createspace to be a relatively easy process, especially as a newbie to publishing.
Once I had my e-book formatted and ready to sell on Amazon, I was offered a chance to enroll in their KDP Select program. KDP Select (Kindle Direct Publishing) is a program for authors that allows Amazon's Kindle Unlimited subscribers to "borrow" their e-book and then receive payment based on the number of pages that are read. Kindle Unlimited subscribers pay a monthly subscription fee of $9.99 and are allowed to borrow up to 10 e-books at any given time. When they are finished reading the book, they "return" it to the lending library and are free to borrow another book.
The author of the e-book will then receive payment for each page of their book that a Kindle Unlimited subscriber reads. Normally this works out to be around $0.0045 per page (yes, less than a half-cent per page!) based on a formula Amazon uses to share their global KDP Select fund (normally around $19 million/month). This fund is divided among all authors who have had books borrowed and pages read. Amazon also has an All Stars program which rewards authors with the most number of page reads per month with substantial bonuses ($25,000.00 in some cases). Achieving this All Star bonus is a significant feat, with page read requirements being well over 2 million (based on KDP Select board comments), but if met, would be a nice bonus and provides Indie authors with a goal to reach.
As part of your contract when you enroll your e-book in KDP Select, you allow Amazon exclusivity to your e-book which means you cannot sell or give away your e-book anywhere else. At the end of the 90 day period, you can enroll in KDP Select again, or opt out and offer your e-book through other retailers.
Now receiving only $0.0045/page read by a customer may seem like a pittance, and it is, but it can really add up. I currently have 2 novels published and enrolled in the KDP Select program. Each month the amount of page reads usually generates about 50% of what my e-book sales (sometimes more, sometimes less) royalties are.
So why would I allow someone to borrow my book when I could sell it to them and get a larger royalty? The answer to that question is really quite simple: people who are enrolled in the Kindle Unlimited program, who pay $9.99/month to read e-books, do NOT purchase and pay full price for e-books. With millions of e-books enrolled in KDP Select which Kindle Unlimited readers can read for "free", why would they pay full price? They won't.
Ultimately the decision to enroll in KDP Select is entirely up to the author, but for me, I think that being enrolled in this program is worthwhile. If I was not enrolled in KDP Select, I might make additional sales through other retailers, but then again I may not. For me, having my work available to the large Kindle Unlimited readership as well as Amazon's global customer base makes sense. Amazon is the global leader when it comes to e-book sales, so why not be with the biggest player and expose your books to the widest audience?