What's your strategy for qualifying new members in free groups?
Here's mine:
I make use of the questions plugin and invite functions.
The first question I ask is how they discovered the group, then I ask if they agree to the no spam policy, and lastly I ask for their email address.
The no spam policy is the first thing I lead with in the Start Here pinned post. I tell them if they think their product or service will benefit the community then they need to DM me with their pitch and, if I think it's of benefit, I'll make a feature post of it.
I use the invite members function to send them a joining link to the email they've provided. This way I can make sure the email they've given is legit.
I also use the no chat and no post until level 2 functions. This cuts down on spam posting.
What are your hints and tips for free groups?