Supplementary Material for: ‘Born in Michigan? You're in the Biobank': Engaging Population Biobank Participants through Facebook Advertisements

<b><i>Background/Aims:</i></b> Despite a broad call for biobanks to use social media, data is lacking regarding the capacity of social media tools, especially advertising, to engage large populations on this topic. <b><i>Methods:</i></b> We used Facebook advertising to engage Michigan residents about the BioTrust for Health. We conducted a low-budget (<i>Results:</i> The Facebook page was viewed 1,249 times during the month of the advertising campaign, versus once in the month prior. 779,004 Michigan residents saw ads an average of 25.8 times; 4,275 clicked ads; the average click-through-ratio was 0.021%. Interactions included 516 ‘likes' and 30 photo contest entries. Cost per outcome ranged from <i>Conclusion:</i> A social media strategy to build public awareness about biobanking is not likely to be effective without a promotional ‘push' to distribute content. Social media advertisements have the capacity to scale-up engagement on biobanking while keeping costs manageable. Facebook advertisements provide necessary access points for unaware participants, with implications for public trust.