One danger of the increasing move to digital payments is the reduction

The old sensation of spending happened during the purchase. Notes disappeared, coins thinned and the remaining cash supplied an immediate verdict. Contactless payment replaces that sequence with a pleasant beep. The transaction becomes smoother at precisely the moment when self-knowledge becomes weaker.

This is commercially useful. Each coffee, upgrade and silent renewal feels too trivial to inspect, while the accumulating total remains elsewhere in time. In the study, all thirty participants underestimated their credit-card spending, by almost 30 per cent on average. Thirty people did not independently suffer the same arithmetic accident. The payment method had separated a series of painless moments from their combined consequence.

Dragging friction back into every purchase would punish the enormous usefulness of digital payment. Feedback can return without making the transfer tedious: a running discretionary total, the annual cost beside a monthly subscription, the amount remaining under a limit chosen by the customer. Timing matters more than moralising. Information arriving after every decision has been made is impeccably accurate and behaviourally unemployed.

There is an awkward incentive here. Sellers benefit when cost is vivid during pricing and faint during use. Twelve harmless-looking monthly amounts can become a substantial commitment without any single moment feeling consequential. That may improve conversion while quietly degrading trust. Convenience and concealment can occupy the same interface; only one of them deserves to be called customer experience.