I wasn't expecting much from it; my goal was to break even on server costs and domain, so ~20$/month. To date it has made $0*
(*technically it did make ~$2 in revenue, but Amazon deactivated that account, I had to sign up for a new one. So my actual received total is $0)
Ultimately it's not a huge deal; I built the project for myself, and it serves me well. I've already discovered 3-4 books I likely would have missed, so I'm super happy to have put in the time!
Lessons learned: When you build a super-niche product mainly for yourself, don't be surprised if it doesn't automatically attract a following. Also, don't set yourself up for disappointment: build stuff because it's fun, not because it's a means to an end.
