Sorry, late to the conversation. I did a deep dive on writing fiction and publishing it on Amazon/Kindle last year. You hit Kindle at the perfect time to make money by doing almost nothing. So many people struck it big back then because there was no competition. Now it's brutal, just like on Medium. It's not to say that you can't make money, it's usually relentlessly publishing books and sometimes giving them away for free as an enticement to read the rest of your stuff. I figured I had better things to do with my time...