Originally Posted by nako
This is not universally true - the Bank of America debit cards still allow mile earning on PIN-based transactions, except for ATM withdrawals, cash-back amounts on purchases, and the purchase of cash instruments (such as money orders, gaming chips, and traveler's checks).
Most supermarkets will let you get "cash back" if you use a pin-based debit card to check out (e.g., you buy $50 worth of stuff, but they run it as a $90 charge and give you $40 cash). And most places that sell money orders will let you buy it as part of the same transaction as non-money-order transactions. For example, at the post office, you could buy a money order and a book of stamps all on one pin-based transaction.
How in the world does BofA know what portion of your transaction is for cash instruments and what portion is for other stuff?