Then you run a email campaign with all the users here who do not have a license in the https://xenforo.com/customers/ and you run a week campaign.
Again, you're only emailing people who don't already have a license, I imagine that could get you 80 new sign-ups easily. That helps the ecosystem for add on developers, and your bottom line.
So if you offered a $20 discount - thats $9600 for 80 people. Could be more signups.. Whats your conversion rate for people who buy add ons or resources?
anyways. just a thought.