Ie Get a new person to join you get a unavailable promo as well as the person joining

There are a few problems here.

If you recruit someone and both of you two get the promo, I don’t. Decipher is going to lengths to let everyone have access to all the cards. If you can find a way to let everyone have access to that card in some other way, it could work. (thinking of something they mentioned about tournament cards, maybe there could be a holo version of a card every month, and something like every player that purchases their first kilo that month gets the card, and the person who recruited them gets that card, and then at the end of a year you allow someone to purchase a 12 pack, one of each holo from the previous year; but then that’s more cards for them to produce and ship and keep track of)

Secondly, you’d want some sort of restriction outside of joining. If you sign up a friend and they join, he could never buy any kilos ever. Then you and he both get a promo. What’s to stop you from doing that with friends who will never play, and getting 2 promos by using him? He should have to purchase some cards first.