Talk of time of day tariffs sometimes hit an impasse when the amount of money that customers can save by moving out of peak time is calculated. It’s often just pennies.

But there is no need for the industry to throw up its hands in despair and give up. Even a quick look at the wide world outside the energy industry shows that customers will react for the tiniest reward – or none at all.

I’m sure we all know people who will drive miles to go to the one garage where petrol is usually a penny cheaper. But think bigger still.

For example, millions of customers join reward schemes where the face value of the ticket is fractions of a pence. Customers are not looking at that number. The real reward may be sports equipment for schools, money off other products in the supermarket, vouchers for experiences and days out, or air miles.

These aren’t being sold on cash but on customer opportunity and interest. And they help the retailer because they meet other aims too. They cross-promote, multiply the impact of other sponsorship spend, or maybe even help clear overbought stock.

The point is, consumers take action in response to interesting rewards. And sometimes, it’s not just swapping beans for cheaper beans. If you think more broadly you can use a small price differential as leverage and make a bigger impact.