Basically instead of a subscription and becoming member of something, you just get a forum for your inner circle and people get lnurl-pay codes they can use to donate. Some amount of donations is required to remain in the group (like x per month), but if you donate more than that on the beginning you can stay until your credits expire.
Every time someone donates a notice is posted in the group page.
Perhaps that could be an @lntxbot feature.