You can cancel Kindle Unlimited by going to Account & Lists ... for the price of a single paperback from the convenience store. Even if you can afford the ongoing cost of an Unlimited subscription ...
With a purchase of an Amazon Kindle Kids you’ll get a one-year subscription to Amazon Kids+, which provides unlimited access ... which is enough to store just about any ebook library.
Amazon is offering three months of Kindle Unlimited membership for free. The offer is however applicable to only Prime members associated with an active US-based account. This happens to be the ...