Here is a recent post from the author of Beneath the Dragon Eye Moons.

https://www.reddit.com/r/financialindependence/comments/12641eu/a_creatives_route_to_fire/

"This year I'm looking at roughly $500k total income on the extremely conservative side, closer to $600k if I'm a little more aggressive with my estimates. Patreon's about half of that, with Amazon being the other half. Within Amazon, KU is 70% of my income."

If you check out their Patreon they are at $30k/mo! So RR will let you build your audience but then you need to monitize those eyeballs somehow at it looks like 50% is Patreon and 50% is Amazon.