It's claimed many shoppers give the machines the wrong information - or steal the goods anyway. Are supermarkets doing enough to prevent self-service stealing?
Richard Dodd from the British Retail Consortium told AOL Money that the costs of stealing are rising for supermarkets. "In our most recent survey, the amount of incidents [theft] had gone down, but the value had gone up."
"Retailers," he went on, "are spending more on retail crime, security guards and CCTV." But there's little evidence on the impact of self-service - yet he says. "Overwhelmingly, most shoppers are honest and do not try and steal," he added.
Well, not according to the study of almost 5,000 shoppers questioned by money website www.watchmywallet.co.uk. However, shoplifting is not always about being poor. Often it's simply about taking advantage of a situation where a shopper feels they've the upper hand.
Cheap veg"A common trick," says watchmywallet, "is to select the cheapest vegetable, typically white onions, when putting a more valuable item through, such as oranges. Half of those who admitted to cheating the system said they selected a cheaper item when putting loose items through."
However AOL Money spoke to Joshua Bamfield, from the Centre for Retail Research and author of Shopping and Crime. He said a survey on self-service theft carried out a year ago indicated no rise in shoplifting.
"But you could argue people have learnt new skills in the last 12 months," he said. "It's possible that if people think they can steal, they will. The [supermarket] industry has got some way to go to prevent self-scanning leading to a major increase in shoplifting."
Quality gearThere are increasing links to shoplifting, two being depression and stress. A trip to the shops can be an opportunity to take control of a situation, according to some psychologists.
Meanwhile some claim middle class staples such as wine, quality meat and seafood - plus IT hardware like iPods - are increasingly targeted as more families attempt to maintain lifestyles in tough times. But there is little statistical evidence to support this.
But the bottom line is that it is still stealing. "If you're dishonest enough to steal, you will steal," says Dodd. "But self-service check-outs are supervised," he warns.