In 2009 Thin Martian started a Twitter campaign for Universal Pictures’ release of Anvil! The Story of Anvil. Working with Universal Pictures’ PR agency, Cohn & Wolfe, they developed a highly effective viral campaign that produced some surprising results. In this insightful case study, Andrew Walker and Steve Parker talk us through the campaign and explain what they learned from the experience. Presented at Social Media Marketing 2010 (London).