RESUMEN
BACKGROUND: There is limited evidence for the effectiveness of social media to promote healthy behaviour among Indigenous Australians, including to reduce smoking. Social media has significant potential to stimulate interpersonal influence to quit, however an important knowledge gap is how and what content people choose to share with friends and family. This paper explores the decision making processes of community members for sharing tobacco control content with family and friends on Facebook. METHODS: Community researchers were paid to choose and share at least one tobacco control post per week for a period of 6 months on their personal Facebook page. They documented reasons for their choices, which were coded and analysed to determine features of messages most likely to be shared, and salient considerations in the decision-making process. RESULTS: Posts which are child-focused, feature Indigenous content, and are perceived as practical, relevant and credible, with a direct and unambiguous message, were most likely to be shared. Posts which included disgusting imagery about health impacts, were focused on the environment, or were ambiguous or sarcastic were less likely to be shared. Decisions were also based on whether content was perceived to contain new information, to be helpful for their friends, and to be consistent with the participant's online identity, as well as the perceived sensitivity of content. The potential impact on expensive mobile data for videos was also a factor. CONCLUSIONS: When designing tobacco control messages to be shared on social media, health promoters should take into account how information will align with positive self-image and can contribute to social capital among the intended audience, and generate interpersonal engagement. Content should complement, rather than attempt to replicate, some message features that are effective on traditional broadcast media. This study shows the potential for health services to incorporate a strategy of using paid local social media 'champions' or 'ambassadors' to disseminate tobacco control messages on Facebook through community networks.