Open the doors to Kindle Unlimited's digital library for three free months

Prime members get all the best deals in July, like today's offer of three free months of Kindle Unlimited . This is a subscription service that usually costs $9.99 a month, but thanks to Amazon's offer, you'll be able to use it for three months at no charge, after which it will renew at that $10 rate each month. You can cancel at any time with no penalties for doing so. The deal is supposed to be restricted to people signing up for the first time, but the miles seem to vary on that.

If you aren't a member of Amazon Prime yet, you should be! You'd gain access to today's deal on Kindle Unlimited as well as all the Prime Day deals that we'll see next week. You can also start a free 30-day trial to make your account eligible for all Prime-exclusive offers and see if you like the service.

Kindle Unlimited gives you access to over a million titles, spanning from technical documents to cookbooks to fantasy novels to nonfiction. Need a self-help book? Want to re-read Harry Potter for the seventeenth time? It's all there, and it's all free with your membership. You don't need a Kindle to read, either. Amazon makes it easy to read thanks to its free Kindle reading apps for iOS, Android, PC, and Mac.

On the other hand, you could jump right into a longer Kindle Unlimited membership at up to 40% off , which is a deal that's good not just for new members but returning subscribers too. The offer won't last forever though.

You can keep up to ten titles at a time, and when you feel like swapping them out, the process is seamless. I'm always shocked at the wide variety of available options. More than a dozen times, I've gone to purchase a Thrifter Kindle book deal, only to find that the title in question is already free thanks to Kindle Unlimited. You can take advantage of thousands of audiobooks, too, if you want to spice up your commute or listen while you cook and clean. The options are almost endless.

Need more awesome ways to save using your Prime membership? Check out our Prime Day hub and be on the lookout for all of Amazon's big deals coming before the big day.