Dr. Augustine Fou discusses several examples of how social media has been effectively used by companies for marketing purposes and provides lessons learned. Positive examples include a TNT video ad that received 22 million views in 5 days, a Kony 2012 documentary video that received 112 million views in a week, and how American Express and JetBlue leveraged feedback and social sharing to launch new products. Negative examples include a problematic #McDStories campaign and a disgusting Domino's Pizza video. The key lesson is that social media can greatly amplify marketing messages for better or worse, so companies must plan carefully and be prepared to leverage social amplification, not just place ads.