The biggest factor in processor costs is actually the card mix, and not the volume that a business generates. To give you some sense, international, AmEx and corporate rewards cards tend to be much more expensive to process. Debit cards, on the other hand, tend to be fairly inexpensive to process for (although, despite the costs mentioned elsewhere in the thread, not all debit cards qualify for Durbin debit rates).

Balanced's pricing matrix only takes one factor (volume) into account. So, for example, if a business accepts a high percentage of debit cards, we can offer a significantly lower rate than the prices in Balanced's matrix.