Visitor engagement and learning, outreach, and inclusion are concepts that have long dominated professional museum discourses.  The recent rapid uptake of various forms of social media in many parts of the world, however, calls for a reformulation of familiar opportunities and obstacles in museum debates and practices. Young people, as both early adopters of digital forms of communication and latecomers to museums, increasingly figure as a key target group for many museums.  This volume presents and discusses the most advanced research on the multiple ways in which social media operates to transform museum communications in countries as diverse as Australia, Denmark, Germany, Norway, the UK, and the United States.  It examines the socio-cultural contexts, organizational and education consequences, and methodological implications of these transformations.