Sainsbury's has paid £60m to take full control of the Nectar loyalty scheme, giving it greater access to information about customer habits.
It said the decision to acquire the shares in the programme from analytics firm Aimia Inc UK was part of a strategy "of knowing its customers better than anyone else".
While consumers will not necessarily see any alteration, the deal means Sainsbury's now has all the assets, staff, systems and licences required for the full and independent operation of the scheme.
The company said the transaction would immediately benefit cash and earnings.
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Analysts said the acquisition represented an opportunity to tap into consumer data fora competitive edge.
"The acquisition of the UK’s largest loyalty scheme brings with it a comprehensive consumer database across a wide range of sectors which will enable Sainsbury’s to better understand its customers’ behaviour and increase opportunities for targeted marketing across its brands, Sainsbury’s, Argos, Habitat and Tu Clothing," commented Paul Hickman, an analyst at Edison Investment Research.
"Potentially, the acquisition enables Sainsbury to rival the functionality of the Tesco Clubcard, including both minute-by-minute consumer spending habits, also bringing strategic insights into longer term trends that will help it adapt its business to the 21st century retail reality.”
Meanwhile, Sainsbury's has announced a giveaway of nectar points this weekend. Shoppers could win an extra £25 worth of points when swiping their loyalty card in stores and petrol stations.