I love change so much opportuntiy to aquire some easy gold.
the expansion means major change and major excitement both add up to dropped defences and a sense of happiness and joy amoungst our customers.
just after TBC is released this baby is going to work - or some variation on it
Write a letter something along the lines of this
Dear .......
congratulations you have survived the challenges of azeroth over many months unscathed and earned the repect of the alliance.
Go now hero through the Dark hole to the new lands beyond and carry the battle to our enemies beyond etc etc
Azerothian gold will be of no use to you in the lands you venture to but i offer you a one time opportunity to exchange some of your gold for 3 times its value in Outand gold to get your campaign off to a good staert etc etc
You are essentially trying to get them to believe that if they cod you say 500g they get 1500 outland gold back but this can only be done once
Some bugger is bound to fall for it and send that cod back to you or send you the gold if you used a straight forward mail
Other versins of this letter could be based arounf jewelcrafting - offering a one off opportunity to receive all the items required to train jewelcrafting to 300 for a one off payment of 100g lets say etc etc