One of the chief benefits of Facebook for marketers is the earned media opportunities it provides, according to a comScore report released in June 2012. Using large brands as test cases and analyzing the impact of this earned media exposure among fans and friends of fans as compared to a control group, the study finds a lift in online and offline purchase behavior among the former group. For example, examining the impact of earned media exposure on online and in-store purchasing at Target, compared to the control group, fans of Target were 19% more likely to purchase at Target in the 4 weeks following exposure to earned messages, while friends of fans were 27% more likely. The testing methodology ensured that both groups had nearly identical levels of purchasing in the 4 weeks prior to exposure. Read the rest at MarketingCharts.