Discourse Auto Remove User from Group

This plugin was developed for the very specific purpose of removing users from a specific group when that user creates a post under a specific category.

You might ask, what the hell is the usefulness of that? Well, I wanted a way to sell ads in a marketplace setting on my forum. When you combine Discourse Subscriptions with this plugin, you can set up the ability to allow a user to place a single new topic in a category of your choosing, then prevent them from creating another until they buy another subscription.