Background:
Open electronic cigarette (e-cigarette) systems allow for "unorthodox" behaviors, that is, the use of the product not as intended by the manufacturer. Surveys provide valuable information on e-cigarette use prevalence, but limited information on the diverse ways in which e-cigarettes are used. This study used YouTube.com, the second most popular social media site in the world, to assess the popularity, prevalence, and characteristics of orthodox and unorthodox e-cigarette use.

Methods:
Staff used search terms (e-cigarettes, vaping, and e-juice) to conduct monthly searches of YouTube videos by relevance and view count between June 30 and November 30, 2016. A customized scraper was used to collect static and dynamic video characteristics. After eliminating duplicates and videos that did not meet the inclusion criteria, 150 videos were viewed and coded independently by two staff. Staff conducted a content analysis to identify the category of e-cigarette behavior (orthodox versus unorthodox) and type of unorthodox use and document the popularity of videos (likes/dislikes). Descriptive statistics were used to calculate means and frequencies.

Results:
Seventy-five percent of all videos showed unorthodox use of the e-cigarette device, liquid or both, with an average of 1,0441,005 view counts compared to 838,966 for orthodox use. Staff identified 9 unique unorthodox behaviors and the most common observed were recreational use (75%) (e.g., cloud chasing), modification of mechanical parts (57%) (e.g., rebuilding), and substance use application (44.6%) (e.g., dripping). Data on popularity showed that there was an average of 14,692 likes and 2,241 dislikes for videos coded as unorthodox compared to 4,549 likes and 736 dislikes for videos coded as orthodox.

Conclusions:
The higher prevalence of unorthodox compared to orthodox e-cigarette use in videos suggests a need to further investigate the influence of YouTube videos on the uptake of these behaviors and harm associated with each type of unorthodox use.