I finished a promotion last week in which the book was free (priced at $0). I finally figured out how to open and read the new report downloaded from the reports section of the KDP account page. To my surprise, there was a delivery charge showing for each book downloaded for free. What happened?
If you've selected the 70% option, then you agreed to have the delivery charge take out of your royalty. For the 35% option you don't get charged.
If you're on the 70% option and then use a free day, they still show the charge as though you'd pay the delivery charge, but the total is zeroed out at the end because the book is still free.
So, no, while all the other figures remain in place, just as they would if you were gaining a sale, the only column that counts is the final royalties column, and that's the one with the zeroes in it. No charge is incurred.
If they have, I think it's an excellent idea.
I agree. Free books are too often worth what they earn for the authors, and many are of poor quality. If there was a charge for delivery of those books, there might be fewer of them cluttering the market (perhaps not). People pay to advertise books that they have to give away.