Amazon recently made changes in the way that Authors are paid for books offered through Kindle Unlimited. In the past, Authors were paid purely for downloads and every author received the same per download as all the others. A thousand page novel would receive the same amount per download as a ten page short story.
This recently changed to a per-page-read model where authors are paid each month depending on how many pages of their books were read as a percentage of the total pages read by all Kindle Unlimited readers.
These changes only affect books offered through Kindle Unlimited on the Amazon Select program. If you’re selling your books through Amazon and are not enrolled in the Kindle Select program then you will not be affected.
This is fair I suppose. Amazon wants to make its customers happy, so they want to encourage quality work to be published. The per-download model encourages authors to produce lots of short works instead of devoting time to fewer longer works in order to make the most money. By changing to the per-page model Amazon is hoping that it will encourage better quality books to be published.
This is not without casualties. If you’re an author of shorter works such as cookbooks, children’s books or short fiction then it doesn’t matter how high the quality of your work is; you’re still going to be getting paid a lot less than someone who’s churned out yet another thousand-page generic fantasy novel.
Should you remove your work from Kindle Unlimited if you write short books? It’s hard to say. If your books are doing well on KU already, it might be worth sticking with it for a while to see how much your income changes. Some authors are already removing their books from KU, meaning that yours are more likely to be read.
It’s worth bearing in mind that removing your book from Kindle Unlimited means your book no longer has to be exclusively available there. You can try selling your book on other platforms and potentially increase sales there.