We already know that from Saltypetra’s stream. Rickygervais also make a great summary here.
Basically, right now it’s just a premium feature tied to real money spending in Guild Shop. Maybe they will expand that to other type of purchases in the future.
Most of the players base won’t get to use it that much. Don’t mistake it for similar Gift system in the game like Candy Crush. It’s a totally different thing here.