Financial times: from nuclear scientist through confectionery salesman to Tesco Personal Finance marketing director, Crawford Davidson's CV makes interesting reading. He gives James Quilter the lowdown.(Profile: Crawford Davidson, Tesco Personal Finance)

If anyone understands the formula that has made Tesco the UK's number one retailer, it should be Crawford Davidson, former nuclear scientist and now Tesco Personal Finance marketing director.

Davidson began his working life at British Nuclear' Fuels (BNFL), before a complete career change saw him working for Mars, starting at the foot of the ladder as a confectionery salesman and working his way up to marketing for Mars ice creams. Marketing roles at Bass followed, before moving to Boots and launching its Advantage Card, which he ran for four years before moving to Tesco as director of Clubcard.

Davidson joined Tesco Personal Finance (TPF) in June 2003, as the business sought to consolidate its foot hold in the financial services market. Launched in July 1997 in partnership with Royal Bank of Scotland (RBS), it covers areas such as savings, home finance and insurance. Now the platform has been established, the aim is to expand the product range while retaining the Tesco colours.

The business is currently in the third stage of its development, says Davidson. The first two stages--taking it from a startup to the point where it is making money--were largely down to the efforts of his predecessor Andy Dewhurst, who moved on to become Tesco Telecom chief executive. The current aim is to …