In a new study being released today in collaboration with Facebook, ComScore looks to show that exposure to earned-media impressions -- or content that a brand's fans or their friends might see organically -- results in more purchases. It also said premium Facebook ads result in more purchases.

ComScore conducted this research with a test group that had been exposed to organic brand content and a control group that had not. The earned-media effectiveness studies used Starbucks and Target fans and friends of fans and followed the test and control groups over the course of four weeks. In the case of Starbucks, 2.12% of the group exposed to organic Starbucks Facebook content had made an in-store purchase after four weeks, as opposed to 1.54% of the group that had seen no such content but made an in-store purchase (a 38% difference). In the case of Target, 3.9% of the group exposed to organic content made an in-store or online purchase in the elapsed month, compared to 3.3% of the group that hadn't been