There numerous benefits to having Amazon Prime, see below for some.
When I shop for nappies for my little assistant using subscribe and save, Amazon has hands down the best value for money.
That said, as an author and a book lover/reader, it is an essential service. As an author, when I enroll my book to Amazon’s Kindle Unlimited program, all those who have Prime membership and own a kindle tablet can read my book without paying anything extra. Another plus is that Amazon pays me a small amount for each page someone on Prime reads.
If you are not already on Prime, I recommend you sign up for the 30 day free trial. You have nothing to lose