The SMBI (Social Media Brand Impact) is a study that measures the impact of social media actions on future brand behaviors. It found that people who engage with brands on social media are twice as likely to visit websites, inquire about products, consider purchases, or buy compared to people who just visit brand pages. Actions involving advocacy like commenting, sharing, following and tweeting have the strongest impact. However, less than a third of people typically take these more engaged actions. The study provides benchmarks to help brands prioritize social media strategies and content.