Dunnhumby Ltd., a marketing agency for consumer goods manufacturers and retailers, said today it has bought BzzAgent, a social marketing company. Dunnhumby did not say how much it paid for the firm.

BzzAgent will become a subsidiary of Dunnhumby, which says it has 30 offices and 1,500 employees in Europe, Asia and the Americas. BzzAgent CEO and founder Dave Balter will lead the subsidiary. He will report to Dunnhumby CEO Simon Hay.

Dunnhumby analyzes shopper data to help its clients better understand customer behavior. BzzAgent works in such areas as brand advocacy and product recommendations. Dunnhumby says the acquisition will enable it to build its expertise in word-of-mouth marketing and related areas.

“Customers’ choices are influenced in many places, and social media and word-of-mouth are playing a key role for brands and retailers,” says Hay. “Not only does BzzAgent leverage a base of 800,000 influential customers in the word-of-mouth space, it is focused on measuring return on investment and the role of social media. With BzzAgent, we believe we can now help our clients understand advocacy and use this knowledge to earn more loyal customers for retailers and brands.”

BzzAgent was founded in 2001. Clients include Procter & Gamble, Unilever, L’Oreal and Michelin. Cowen and Co. was the financial advisor to BzzAgent for this deal.