Social marketing seeks to develop and integrate marketing concepts with other approaches to influence behaviours that benefit individuals and communities for the greater social good (International Social Marketing Association, 2013). Online social marketing campaigns are an increasingly popular strategy for engaging, informing, and influencing young people on issues relating to their safety and wellbeing. As a result, there is much interest in the role of online campaigns in promoting safety and wellbeing amongst young people. Whilst industry-informed evidence exists in relation to any campaign’s reach and impact, there is limited evidence in relation to the efficacy of these approaches for actual attitude and behaviour change. This is due in part to the complexity of working ethically online with minors, who require informed parental consent to participate, and the interdisciplinary and collaborative approaches required to measure and test change through online contexts. The theoretical and methodological challenges associated with mapping/tracking online engagement and determining subsequent attitudinal and behavioural change, along with innovative methodologies, required for youth-centered campaign design and development, also exacerbate that complexity. Significant advances in the science of impact evaluation are needed in order to bridge offline research standards with digital practices and data collection. To address these challenges, and contribute to new knowledge in this area, the Safe and Well Online project brought together researchers, digital strategists, young people, creative agencies and industry partners to specifically examine how online social marketing-styled campaigns can effectively address attitudes and behaviours which could compromise young people’s safety and cause harm. This report describes the Year Two/Campaign Two processes, and articulates findings from the major project components designed to address the challenges noted above (see Figure 1). Three major components comprise the Safe and Well Online project: 1) A participatory design (PD) process involving young people and sector partners (UWS) for; 2) campaign development (Zuni & Digital Arts Network); and 3) a cohort study (University of South Australia) to evaluate campaign effectiveness and attitude and behaviour change. Each sub-study comprehensively considered the ethical requirements of conducting online research with minors. The theoretical and methodological framework for measuring campaign engagement and efficacy (Sub-studies 3, 4 and 5) drew on the Model of Goal Directed Behaviour (MGB) (Perugini & Bagozzi 2001) and Nudge Theory (Thaler & Sunstein, 2008). This report extends the findings and conclusions of the Year One Pilot Study ‘‘Keep it Tame’’ (Spears et.al, 2015), and details the development and evaluation of the second of four Safe and Well Online Campaigns—‘‘Appreciate A Mate’: Helping others feel good about themselves’.