“…Twenty-one publications examined the claims and promotions in e-cigarette advertisements (studies are listed in Supplementary Table 1). Of these, four were descriptive studies of e-cigarette companies' and retailers' marketing, 19,20,25,30 twelve were content analyses of e-cigarette advertising, [21][22][23]26,28,29,31,[33][34][35][36][37] one was an e-cigarette retail audit, 27 one was an analysis of national e-cigarette advertising data, 24 two were focus group studies of e-cigarette attitudes and perceptions, 38,39 and one was a cross-sectional survey of the correlation between marketing claims and e-cigarette use. 32 Eight studies of e-cigarette advertisements conducted between 2010 and 2015 found that, compared to combustible cigarettes, e-cigarettes were presented as healthier, 20,22,24,28,31,39 less expensive, 22,24,26,37 more socially acceptable, 28 unhindered by smoke-free policies, 24,26 and more environmentally friendly.…”