maybe a new optional gem only weekly/monthly chain that will randomly reward a worthy gem only fixed/useful item: wondrous residence, extra mma, extra explorer, pfb, training ground. you know, items that will make players go for it and have a game long use
this might work if there wont be silly rewards like: buffs, resources, books, decorations....
as an ex: you pay 10k gems to start it and at the end you get a random reward (8k-15k gems worth)
