The biggest challenge is getting the word out and getting people to come for the event. If you can get people to come, we can do our own free fly event. A paid player can set up a custom arena, and non-subscribers can play in the custom arena. I have tried to use this feature to set up events for prospective players, but I couldn't find a way to get prospective players to come.
If you do a free arena once a month, then you could have a small group of volunteers to coach the new guys and advertise the game.