The rate of e-cigarette ever-use tripled from 7.0% in 2012 to 20.0% in 2014. After adjusting for sociodemographic variables, smoking status (including susceptibility), and other factors associated with tobacco smoking uptake, e-cigarette ever-use was associated with gender, smoking status, close friends' smoking behavior, and risky substance use. Among smokers, desire for a cigarette, quit intention, or past-year quit attempts did not predict e-cigarette ever-use. Irrespective of smoking status, curiosity was the most commonly cited reason for trying e-cigarettes.