I hadn't done the math per user yet.

We've currently made 30 sats per registered user (15,000/500) or ~75 sats per monthly lurker cumulatively over a 3-5 month period so let's roughly say 10-20 sats/user/month. So we're looking at more like $500-$1000/mo at current prices with 100k users (assuming the product freezes in terms of monetization or engagement/user).