1 The number of individual social media users on each platform that fit the desired demographics of the target population and could be potentially shown the advertisement during the paid advertising campaign. 2 The number of social media users on each platform that were shown an advertisement during the campaign. 3 The number of social media users that clicked on the advertisement on either social media site and were successfully transferred to the survey landing page on Typeform.com to begin eligibility and informed-consent questions. Not all social media users targeted by the paid advertising campaign were eligible or gave consent to participate in the survey. 4 The number of eligible and consenting survey participants who could potentially complete the full survey.</p