A new study

has revealed for the first time the true cost of supermarket loyalty schemes and money-off vouchers. Half of shoppers say such vouchers lead to overspending, shopping more frequently or buying what they don’t need just to qualify for ‘money-off’. The survey was carried out for Aldi, which naturally doesn’t do that sort of thing, and is based on opinion. But it seems spot on.

Those ‘3 for 2’ offers also promote food waste, responsible for 10% of carbon emissions. If food

waste were a country, it would be the third biggest carbon emitter after the USA and China.