Under the terms of the contract, GB Group's Data Management & Insight division will continue to provide cleansing and enhancing of WH Smith's Clubcard holders, as well as hosting a database for marketing purposes.
Mark Bramwell, senior project manager at WH Smith, said: "Our Clubcard has proven to be extremely popular and it has also become a vital part of building a complete picture of our customers. With up to 250,000 daily transactions and the service continually growing, it is vital that we have a resource we can rely on and GB Group has a proven track record of working with us in this area."
WH Smith Clubcard launched in 1997 and attracted 2.5m members in the first six months.
The retailer announced last year that it was opening up its loyalty database to third parties in a deal with list management firm Swetenhams.
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