Main idea

A card commission of a few percent is, for an established business, a cost line you negotiate once a year. For a beach vendor or a hairdresser working from home, it is a direct share of what she takes home that evening.

Hence a practice you can observe in the State of Rio: the customer offers to pay by instant transfer rather than by card, and does so as a favor to the seller. The motive is neither speed nor security, it is not to take those few percent away. Choosing the means becomes a gesture of mutual help.

What this shows goes beyond Brazil: a cost gap judged negligible by whoever designs the system can be decisive for whoever collects on it, and that gap is enough to decide which means prevails.

Why it matters

For whoever sets pricing, this shifts the question: a rate isn't judged in the absolute but relative to the income of whoever bears it. The same percentage can be invisible on one segment and prohibitive on another.

And it explains adoptions no campaign produced: the means that costs the seller least spreads through the customers themselves.

Nuances and limits

This sensitivity holds for actors with very thin margins; it fades as soon as volume allows the cost to be absorbed or passed on.

And the cost of collecting isn't the only determinant: physical risk and simplicity for the customer also play, sometimes in the opposite direction.

Open questions

• At what income level does commission stop being a criterion of choice and become a cost line again?