s still time to sign up and lock in this promotional offer. You And as a Prime member, there's a good chance you can get these services for free — at least for a limited time. With Prime Big Deal Days on the horizon, Amazon isdishing out dealsleft and right, including on its subscription services. Kindle Unlimited is a paid subscription service offered by Amazon to feed your reading habit. The main differences, besides the cost, are that there are no wait times for popular books and no time limits on borrowing books.