Package-goods brands are still cautious about social media, figuring that the return on investment can't be accurately measured. After all, marketing on Facebook or MySpace might generate a conversation but not necessarily a sale. Now, however, a method is emerging to relate one to the other, potentially eliminating a major impediment. Recent research from ComScore, MySpace and Dunnhumby presented at the Advertising Research Foundation's Re:Think 2009 conference in late March suggests that even relatively small outlays on social networks by package-goods brands can result in offline sales impact and deliver positive return on investment...