MacMoney is a special way of paying for items at the Used Apple Store. When you use MacMoney to pay for your purchases and repairs, you get a 5% discount.
You can put money into your MacMoney account by using a check, cash, or trading in old equipment. You also earn 2% annual interest on the average balance per year paid out monthly. This is almost twice as high as keeping your money in any bank.
MacMoney also has a special investment option, whereby there's a 12% interest rate per year. The money cannot be used for one year.