By spending £10 or more and swiping their Nectar card at Sainsbury's stores during July customers have the chance to win one of 12,010 Nectar prize points packages.
The promotion also includes an online component, created by interactive promotions company ePrize, which links to the in-store promotion.
Each game card provides a one in three chance of winning in-store, but players can also get an additional chance to win by visiting and entering the unique code on their card.
Visitors to the online promotion site can play a click-and-win game, by popping virtual balloons for the chance to win prizes.
John Sheekey, Nectar marketing director, said: "No one walks away empty-handed in the 'swipe to win' promotion. By working with ePrize we are able to extend our successful offline Nectar points programme online to create more excitement and more ways to engage with our customers."