I am a publisher on Amazon's KDP service. I asked them if I could get royalties in Bitcoin and they said:
Hello,
Thanks for writing in.
We currently pay royalties via paper check, wire transfer, or Electronic Funds Transfer (EFT) based on the location of your bank account. We do not offer alternative payment methods such as Amazon Payments, Payoneer, or PayPal, at this time.
For more information on getting paid or changing your payment methods, please visit our Help page:
https://kdp.amazon.com/help?topicId=AE24XS35AM53PHowever, incorporating Bitcoin as one of our payment methods is a great idea. In fact, we've already submitted it to our business team for consideration. They will definitely take it into account as we plan further improvements.