When the fee is clearly higher than what it's costing them. Either by the percentage itself, or often, a "minimum fee amount" that really exceeds the actual co

When the fee is clearly higher than what it's costing them. Either by the percentage itself, or often, a "minimum fee amount" that really exceeds the actual cost. A $2 minimum charge, for example, is somewhat common for things where the item/service is often much less than $100.