The service combines survey research asking respondents what brands they most often recommend positively or negatively, with social media monitoring, identifying positive and negative comments about brands in blogs, online forums and social networking sites.

It is initially being used to rank restaurant chains, with California Pizza Kitchen heading the first list of the most recommended brands.

Merrill Dubrow, president and CEO of MARC, said: “The Recommendation Index looks not just at how consumers talk but at their actions. We wanted to move from the hypothetical to the actual.”