How to publish a FREE ebook on Amazon Kindle
So, you've published a book on Amazon Kindle and you want to set the price to zero. There are many reasons for this - offering the first book in a series for free, offering short stories free, etc, etc. Unfortunately, when you publish an ebook for the Kindle (on KDP) the minimum price is 99c ... and you can't go any lower. (In this article I'm using Amazon US pricing.)
So how do you make it free?
Here's a brief rundown of the steps involved:
After you've published your ebook on Amazon KDP, head over to Smashwords and publish the same file there. Ensure the title is the same, but this time set the price to $0.00 (Smashwords allows free ebooks.)
After you've successfully published your ebook on Smashwords, apply for a free ISBN. You'll need this to enable premium distribution. (If you want, you can buy an ISBN in your own name, which allows you to specify the name of the publisher. Otherwise it'll be 'Smashwords'.)
At this point your Smashwords ebook will be marked as 'requires submission' or 'pending approval'. You can't enable premium distribution unless with your ebook file is absolutely perfect - and Smashwords can be very picky. Keep fiddling and uploading until your file passes all the tests.
Your title will be 'pending approval' for a while. In a couple of weeks - or longer - your book will appear on B&N and Apple iTunes with a zero price. Now for the good part ... click 'report lower price' on the Amazon listing for your ebook, and paste in the precise URL for the B&N listing, a price of zero, and the current date. Then repeat with the iTunes link.
try reporting the lower price on Smashwords before your title is available on sites like B&N and iTunes, but I'm not sure whether this will work.
The next part is up to Amazon. Sometimes they'll price match and set your book to zero, and sometimes they won't. I can't tell you how long it will take, or whether they'll ever reduce the price to zero.
One final comment: After your ebook is priced at zero on Amazon, if you change the nominal price of your ebook on Amazon (e.g. from 99c to $1.99) it doesn't cancel the zero price.
Reverting the price
What happens when you want to cancel the zero price? What you need to do is raise the price on Smashwords, then wait for Apple and Barnes & Noble to pick up the new retail price. Once they do, Amazon should follow suit.
I hope that sorts out some of the confusion, and best of luck with your publication!