Tesco's policy of sending money-off vouchers to customers who buy a lot of wine has been questioned during a Commons grilling over loyalty schemes.
The government is targeting people who drink at home
Chairman of the influential Commons home affairs committee, John Denham, said the supermarket giant's Clubcard scheme could encourage alcohol abuse.
But Tesco's Nick Eland insisted the firm marketed goods responsibly.
He told MPs it would never use loyalty cards to promote tobacco or baby milk but it would send out "wine coupons".
The Commons home affairs committee is investigating whether Britain is turning into a "surveillance society" and was taking evidence about shopping loyalty cards.
Mr Eland, Tesco's legal services manager, told the committee his firm collected information on spending habits from customers who used its loyalty scheme so it could target offers at them.
Asked if that meant Tesco, which is Britain's biggest retailer, would try to sell more wine to people who were already buying a lot of it, he replied: "We would probably send a wine coupon, yes, if it is relevant."
Mr Denham questioned whether this was a "responsible" approach to marketing, "in view of the government's alcohol strategy this week".
"I don't quite see why Tesco should be trying to raise the consumption of high fat products, or high fat and salt or high alcohol products because that is what somebody is already buying," said Mr Denham.
"Where does the level of responsibility beyond selling as much as you can of whatever harmful product it is the consumer is buying stop?"
Mr Eland told the MP: "We constantly contact and speak to our customers to understand whether what we are sending is appropriate to them and if we fail to do that our customers would let us know by not using the scheme."
Mr Denham replied: "I may be an alcoholic. It may be that sending me wine vouchers is not actually a particularly benign thing to do."
Mr Eland said: "There are certain areas we recognise. We would never promote tobacco or baby formula or those kind of areas.
"I appreciate the point you are making but we are running a loyalty scheme and ultimately we have to rely on our customers to make the decisions in relation to the information we provide them and the offers we provide them."
The government's latest alcohol strategy, published on Tuesday, is for the first time targeting older people who drink at home, as well as young binge drinkers.
The campaign will seek to alert, for the first time, those who enjoy a bottle or two of wine at home most evenings of the possible long-term health risks.
Mr Denham also said customers should be told if spending patterns identified through the Clubcard scheme were being used to identify areas to build new Tesco stores, which he said could put local district shopping centres "out of business".
Mr Eland said the information is used "used primarily for the benefit of customers," but he added: "I can't give you great detail about how our insight units may use it in the ways you're suggesting."
Mr Eland said information gathered by Tesco's loyalty scheme was kept for two years.
He said it was not shared with outside agencies, but the company did hand details to the Home Office if requested, for use in court cases or by the police.
"We have 13 million active customers and I believe in the last year we have had less than 200 total requests and the majority of those are from customers themselves," added Mr Eland, who said the issue had to be viewed "in context".
Martin Briggs, corporate affairs director, Loyalty Management Group, which runs the Nectar loyalty card scheme used by rival Sainsbury, said it also cooperated with the police, under data protection laws.
"This applies in very limited circumstances, in terms of basically investigation of criminal activities, and is not just a general permission to disclose everything we have to any government agency that may wish to receive it," he told the MPs.
But he said Nectar cards, which are used by several different companies, did not collect data on items purchased, just the total amount spent, the location of the store and the date and time of the purchase.
Mike Bradford, director of regulatory and consumer affairs, of credit reference agency Experian, said efforts had been made to improve "the accuracy and the amount of information" held on people in recent years.