Advertising group WPP is reportedly preparing to make a GBP2bn swoop for the Tesco-owned data operations business Dunnhumby -- just one month after splashing out GBP800m on an IBM contract to upgrade its global technology platform, enabling the launch of new digital services. In recent years WPP has grown its revenue from data marketing operations to £10bn, representing just north of a quarter of the group’s total annual income, but faces the prospect of a bidding war for its latest prize catch.