Psychology research on value perception of different pricing models?
mseebach: I can't point to any research, but it seems the bias lately is "keep it simple", which would point to your second option.You can add a simple "expiring credit" function like Skype has (if your account is untouched for a year, they tell you to begin using it, however little, or lose it) to keep your books sane, and a service to transfer money out for e.g. a $10 fee.