Dunnhumby may not carry the same brand name recognition as Tesco, but the marketing firm is credited with catapulting the supermarket giant from being merely hugely successful to stratospherically so, thanks to its work on the Tesco Clubcard loyalty scheme. Husband and wife team Edwina Dunn and Clive Humby set up the company 17 years ago in their west London home. Each time a shopper hands over their Clubcard at the till, the items bought are noted so that customers can be placed into specific groups. Dunnhumby analyses when people shop, how they pay and even how many calories they will consume, making marketing to them a far more sophisticated and relevant business.

Since first winning Tesco as a client in 1994, the firm has gone from strength to strength. Profits and sales soared by 50% last year. And while Tesco now owns an 84% stake in the firm, Dunn and Humby resisted a complete takeover. With such a shiny future it comes as no surprise to learn that staff are excited about where the company is going, giving this point a positive score of 84% — the sixth highest result for this measure in the list. Staff know their contribution counts towards its success, rating this question a top 30 score of 79%. They also think the experience they are getting at Dunnhumby is good for their future (81% and a top 20 rank).

The company believes in sharing its success. Salaries are generous and staff get a good set of flexible benefits. These include private medical care, dental treatment, critical illness and life assurance, plus a noncontributory pension scheme. Everyone gets £350 per year to spend on leisure activities of their choice such as city breaks, renting a canal boat or paying for a course of health therapy. The in-house gym is free to use while softball, volleyball and games teams play throughout the year. Pool and table football facilities provide a lower octane workout.

Social events last year ranged from salsa dancing to a scavenger hunt. There is also a company book club. Due to such a persuasive combination of professional and social features, employees would strongly recommend a job at Dunnhumby to others (77%).

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