This is the major move, much bigger than just boosting sales of Kindle and Amazon Prime. Amazon is testing a books by subscription service. They're using Kind

This is the major move, much bigger than just boosting sales of Kindle and Amazon Prime. Amazon is testing a books by subscription service. They're using Kindle owners with Prime to limit their test market to good loyal customers. They're limiting the number of books you can check out to control their costs during the test, but it's likely the copyright owner gets some payout per read. With this limited test Amazon will understand the business model and technical requirements to roll this out on a much larger scale. I expect we'll see an Amazon book subscription service for all Kindle readers with a payment plan based on the number of books you can check out at a time and the number of books you can check out per month.