Sheri and I LOVE Amazon Prime. Because we have Prime, we have Kindle lending library privileges.
We both have Kindles. She has the paper white version and I have the HD6 (and older unit). When I use my Kindle Fire, I always have 3-5 books pre-bought and downloaded to it so I always have something to read.
Kindle has got me to reading much much more. That and my special close-in glasses I purchased after I had surgery for diplopia. That story is for another day though.
If you don't want to do Prime however, you could use this Kindle Unlimited capability to get more reading than you should shake a stick at.
I love the Amazon system and while I prefer to buy the books I want to buy, I'm thinking that this would be a gangbuster way for folks who love to have some randomness thrown at them. I know that I put my ebooks on Amazon Kindle Unlimited – in fact one is still there (at the time I wrote this article). Additionally, if there is an audio version it looks like you get that as well with your books.
I spend FAR MORE than $9.99/month on books so this seems like a neat deal.
Check it out and let me know what you think RVers!