The region wide WoW Token auction house could have a huge impact on a servers economy once in place! Imagine buying a Token and the seller wasn't from your server. *Poof*, that gold is gone. On the flip side, the seller of this transaction gains gold that wasn't on the server already; Blizzard crates that gold "out of thin air" when this happens. Introducing gold that wasn't there before in large quantities could from Token sales could impact a servers economy. If there was server specific WoW Token auction houses, the gold would be shuffled around players while keeping the economy at it's current state. But that could limit the availability of the Tokens and at time have zero up for sale. So the region wide auction house solves the issue of always having tokens for purchase.