If you are a Prime member on Amazon, you already know how valuable it can be. I love the 2 day free shipping and have a tendency to check Amazon first before I drag my fanny around town looking for something.
There is another reason for getting and keeping a Prime membership on Amazon. Many authors make their books available to the Kindle Owners' Lending Library. Read Harry Potter for FREE with nothing more than your Prime membership. Borrow free with no due dates.