It costs zero to upload a book to Kindle. Zip, nada. It might be trash or treasure, but the “gate” is wide open to indy authors. In fact, largely due to Bezos and Amazon, the “real” publishing world gatekeepers are no longer even relevant. Anybody can publish anything, for free.
Promotion and selling is still up to the author, but at least it’s an open and level playing field. No more years wasted playing “entice an agent” and groveling on your knees up and down 5th Avenue kissing the P.C. backsides of covens of liberal witch gatekeepers.
How does that work when you have the days that you give them away? Does Amazon do it for free as a promotional item?