Great questions, this can be a major challenge how to do onboarding for the normies.
The primary concept for Discourse seems to be “Community,” so for someone to join means they have opportunity to contribute + participate in the community.
One strategy I’m considering going with is to use discourse as a requirement for potential clients to create an account with for screening process to evaluate if it will be possible to work together or not. Policy would be: if people aren’t willing to create account, then I can’t work with them.
Not sure if anyone else has tried that strategy or would recommend other strategies.