The humble text message, first devised in 1984 with the first message making its way over the mobile airwaves in 1992, is credited with this particular good deed.
A simple SMS alerting HSBC customers that they are about to go into their overdraft was introduced towards the end of 2014.
Since then, the bank claims it has saved customers a combined £100m in fees.
This combination of behavioural science facilitated by technology isn't necessarily coming through the medium of text message, however - though it may be the easiest method. The bank has already sent more than 25m of them and half its customers have used the reminder to sort it out and avoid a charge.
The bank introduced its "nudge app" at the start of the year, designed to help monitor spending and change those bad habits into better ones, while this kind of spending management is also being trumpeted by the digital challenger banks looking for a slice of the big four banks' business.
Mondo, recently handed its official banking license, monitors spending and provides notifications, while a soon-to-launch feature will offer customers the ability to set targets for spending (and saving).
The wide-ranging review of retail banking by the competition watchdog just a few weeks ago also zoned in on the ability of technology via the now ubiquitous smartphone to change the way we bank, identifying poor customer interaction and engagement for the sorry state of the current account market today.
All banks will soon be forced to send such alerts to customers who go into an unarranged overdraft as part of the reforms, which could save Brits millions more.