Hey buddy. You can get invited by a friend, this would be the normal procedure I guess. But to get the whole thing started there need to be ‘random’ invites. In the case of Redworx I believe old and active users were choosen to receive an invite code for themselves and another one for a friend.
Right now every newly invited member is allowed to invite one person so it becomes a chain. Additionally the invited have to remember that breaking certain rules results in the whole chain banned back to the origin which is the first invited person. At least that is how it is currently handled.
I wanna point out that I don’t know for sure why I have been choosen.