OP's rounding suggestion doesn't seem to work with my Citi AA or Amex SPG cards.
Originally Posted by
Legionayr
The merchant will typically be charged a transaction fee (fifteen or twenty cents per transaction is usual) by his/her credit card processor, in addition to a percentage of the total amount, so good luck in finding one who will permit you to make a long series of tiny transactions!
Obviously, people push the boundaries at big stores where the employees don't give a rat's arse, not small mom-and-pop shops.