In the absence of the kind of federal regulations that apply to tobacco cigarettes, television advertising for e-cigarettes has increased two-fold for youth and three-fold for young adults in the U.S. in the past two years, according to a study. Researchers found that youth exposure to electronic cigarette advertisements increased by 256 percent from 2011 to 2013 and young adult exposure to e-cigarette ads jumped 321 percent in the same time period.