Methods and a system for exploiting the secondary traffic generated by social networking sites are disclosed. Traffic on a commercial website is constantly monitored by a web analytics tool, which collects traffic measurements of hits, button presses, enquiries, purchases etc., as well as the referrer URL of a site such as a social networking site through which the commercial website is accessed. The collected measurements are forwarded to a Referred Traffic Analysis System. Concurrently, the Referred Traffic Analysis System crawls the Internet and collects a large number of social networking sites, analyses their content by extracting insight terms and phrases from them. In a third step, the collected traffic measurements are correlated with the collected insights from the social networking sites, and the top insights that reoccur frequently enough to appear to be a driver for the measurements observed, are presented to the client. A corresponding system is also provided.