Content analysis of age verification, purchase and delivery methods of internet e-cigarette vendors, 2013 and 2014

OBJECTIVE: Identify the population of internet e-cigarette vendors (IEVs) and conduct content analyses of their age verification, purchase and delivery methods in 2013 and 2014. METHODS: We used multiple sources to identify IEV websites, primarily complex search algorithms scanning more than 180 million websites. In 2013, we manually screened 32 446 websites, identifying 980 IEVs, selecting the 281 most popular for content analysis. This methodology yielded 31 239 websites for screening in 2014, identifying 3096 IEVs, with 283 selected for content analysis. RESULTS: The proportion of vendors that sold online-only, with no retail store, dropped significantly from 2013 (74.7%) to 2014 (64.3%) (p