I was thinking about some kind of lottery for Guild Wars, that you can maybe buy a ticket for 1k and that each week Anet anounces the winner. Maybe Item or Gold Awards...
Hey.. I saw this one before...
how come you didn't ask % of the prize goes you to as well?
Overall.. bad idea...
however, some sort of "gambling" (like the skill charm gambler) mini-game might be a good gold sink.... (I want Cards and Card collector, where you can pay to get one of the random cards... )