Facebook has become a highly attractive advertising medium, but effectiveness and how the channel works are still little understood. Metrics such as 'likes' are available but offer little insight. We believe that social media work differently to conventional ads, but just how do they work, and how well? this research used a new implicit test (iRt) developed by Cog to track effects from two social media campaigns for a major brand, and the effect of each in combination with mainstream TV advertising. the research took place within Facebook pages among users, and provided dramatic evidence of how effective social media campaigns could be, and how different approaches produced different outcomes.