and/or the ability to gift credits to other players (if it can't be done already)
The only issue I can think of is with the complaints Tiny Speck might get about credit card fraud and what not.
Look at EVE online and the ability to sell subscriptions has HELPED the economy. And since subscribing in Glitch, gives little benefits in game other then Vanity items and convenience I believe the ability to sell subscriptions could do alot for the game. =)