Of course, any discount system would need a way to prevent farmers and groups of players from trying to co-op their way to cheaper subscriptions. I believe there's currently a limit on how many accounts can be paid by a single credit card. What other checks and balances could you put on a discount system to keep it fair? Can we think of ways to set reasonable limits without requiring onerous levels of identification and verification?
And what about the economics of server transfers? It seems logical that there be a financially reasonable alternative for moving an entire realm's worth of characters from one realm to another -- or at least some discount for multiple characters. I know so many players who categorically rule out transfers that would improve their quality of life (scheduling, realm population, raiding groups, friendships...) because they can't afford to move all the characters they've grown to love. Give us your ideas! Because when it comes to our characters in WoW, it unfortunately takes more than love to keep us together.