You make some very good points. I should have posted behind the paywall a lot sooner on Medium. Started only 2 weeks ago marking my articles paywall only, and made $209 within the first week, and looking at a total of nearly $500 after 15 days. But, like you said, it didn't really happen out of the blue, I had years of (light) Medium presence. Been looking at Amazon myself. What worries me is the editing part. For instance I have a 400 page novel in draft and getting an editor to look at it would cost me nearly 10K. That's a huge investment that I am not sure I can justify to myself.