MY NEW IDEA !!!!!
You should make that players can donate things to each other (stamina, equipment, soulstones, coins, diamonds ...)
How is it work?
If the player decides to donate some things, player mark things and how to donate, than that player gets a promo code and gives that PROMO CODE to player which he wants to donate. PROMO CODE can be used ONCE !!!
How is it looking now:
How will it look with this possibility:
(Click donate and you will get promo code)
And other player put that code here:
That's it! Hope you will pass it to your team!