Participants in a laundry room must decide whether to pay for separating their laudry into color and white.
When paying with coins, 44% separated their laudry into two separate loads. in contrast, 65% did when paying with a prepaid card.
We tend to be more willing to pay when there is no physical money involved in a transaction.
See the full study here :
Soman, D. The Effect of Payment Transparency on Consumption: Quasi-Experiments from the Field. Marketing Letters14, 173–183 (2003). https://doi.org/10.1023/A:1027444717586