**Update: It turns out that Kobo delivers books in two formats, encrypted epub, which Calibre handles with no problems, and Adobe Digital Editions, which I can't get to work via Calibre. If you scroll to the bottom of the book detail page on Kobo it tells you the format, so be aware and don't buy if it's ADE. I spend money and screw up so you don't have to :)
Amazon would have you believe you can only read e-books on a Kindle if they come from Amazon. They are partly right. You can only directly load Amazon e-books, or unencrypted e-books, directly onto your Kindle. So what if you have a Kindle but want to give Amazon less of your money next year?
I have an answer for you.
Kobo is a competing e-book provider. Over the last few days I've checked about a dozen book prices on both Kobo and Amazon, and the price has been exactly the same every time. So saving money is not an issue here. With just a little bit of extra work, you can buy e-books from Kobo and read them on your Kindle. A bonus of this process is that by decrypting the e-books you free them up to read in whatever e-reader comes next. You won't be locked into any proprietary e-reader device.
Step 1: Install Calibre on your computer. Calibre is an e-book library program that organizes your e-book collection. It's very cool software even if you aren't using it to decrypt e-books.
Step 2: Install the DeDRM plug-in for Calibre.
You are now ready to free your e-books. When you buy an e-book from either Amazon or Kobo, simply download the e-book directly to your computer. Then add the e-book to Calibe using the "Add Books" button in Calibre. When it imports the book it will automatically strip the DRM that limits where you can read the e-book. If you can read the e-book in Calibe the decrypt process worked. Now all you have to do is get the new, clean e-book back on your Kindle. If you keep your Kindle near your computer you can simply plug it in via USB and transfer it directly. You can also use your secret Kindle e-mail address and mail the e-book to yourself.
Note - this only works if you download the book to your computer, then it move to Calibre. If you load directly to your Kindle after buying that copy will be locked up forever. You can always replace the locked up version with a clean version.
You should also download all your existing e-books from Amazon via the Manage Your Kindle page, then load those downloaded copies into Calibre. Then back those clean copies up on Dropbox, Google Drive, etc. so you have them if / when your Kindle fails.
In case you are wondering...
Is this legal?
Maybe? My understanding is that we have a legal right to back up software and you can't really back up software if it's encrypted and you don't have the key. However, I'm not a lawyer and this is not legal advice.
Is this ethical?
100% yes. When you buy a physical book it doesn't come with restrictions that limit where you can read that book. You can loan your physical book to a friend and it's 100% cool. Why is it different just because the book isn't printed out? Also, if Amazon gets in a spat with a publisher books can vanish from your Kindle. Ironically, that famously happened with the book 1984 a couple of years ago. By storing decrypted copies of your e-books you protect yourself from being locked into a single e-book ecosystem. If your Kindle dies you can replace it with an alternative and not lose the books you already paid for.
The only unethical actors here are the book companies that insist on DRM. MP3 files are sold open and it hasn't killed the music industry. Open e-books would not kill the e-book market either.
This is entry #18 in my attempt at 31 days of blogging for December 2018. I've haven't posted here daily since about 2007, so this should be interesting.