First off, everyone knows that Runecloth is the MOST sold item in WoW ever. It always has acutions on AH and everyone farms this. Easy to farm, even easier to sell.
So i tought of a way.. one day i was sending c.o.d stuff and i missed out some sending the item and gold instead. Only noticed 3 days later.... why not take this as an advantaged?
I made a lvl 1 called Runybank, and spammed trade channel for 3 days with this message "WTB all stacks of [Runecloth] 2.2g EACH!!"
Now when i came to the mailbox i had, around, 1450 stacks in there, most of them were c.o.d ofc , but some were runes + money sent by players. Total winnings were 330g +- and 150+- Runecloth stacks. Free runes, free money.