How? My Kindle's quite old (4th gen, I think), it doesn't even support epub files. (I convert epubs to mobi to use on it.)
As far as I know, you can't use the ACSM files Amazon on it. I can't convert them to anything because Adobe hasn't released a version of Digital Editions for my operating system.
Technically, I could set up a Windows vm. But requiring a customer to use a particular OS to read a friggin' book is lunacy.
It's not the only option, a Kindle can read Kindle books from Amazon that you've admitted sell for $5.