A new United States study revealed that when it comes to e-cigarettes, online advertisements are what drive teens to purchase the products the most.

With its rise in popularity in recent years, big U.S. tobacco companies are jumping on the e-cigarette bandwagon, creating their own battery-powered gadgets that can turn liquid nicotine and other flavorings into a vapor that is then inhaled.

The researchers that headed the current study analyzed data from a recent nationwide survey of approximately 22,000 middle school and high school students in grades six through 12 in order to determine the ad format that persuaded teens to purchase e-cigarettes the most effectively.

The results revealed that middle school children that were routinely exposed to e-cigarette advertisements online were almost three times more likely to use them than their peers that did not see the advertisements. Furthermore, high school students that were exposed to online advertisements frequently were approximately two times more likely to use e-cigarettes.

"E-cigarette ads use many of the same themes used to sell cigarettes and other conventional tobacco products, such as independence, rebellion and sex," said Tushar Singh from the U.S. Centers for Disease Control and Prevention and lead author of the study. "The situation is compounded by the fact that e-cigarette online vendors are using social network services to market their products - and many online vendor websites are very easy for youth to enter and make purchases."

The data from the study was obtained from the 2014 National Youth Tobacco Survey, which asked teens how often they used various kinds of tobacco products as well as how often they were exposed to advertisements for the products.

In terms of other forms of advertising, middle school students who saw newspaper ads for e-cigarettes "most of the time" or "always" were 87 percent more likely to use them compared to their counterparts that never viewed ads. In addition, high school students that routinely viewed newspaper ads were 71 percent more likely to use e-cigarettes.

Regular viewing of e-cigarette advertisements on television and in movies was connected to 80 percent higher odds of middle school students using e-cigarettes and 54 percent higher odds for high school students in comparison to their counterparts that were never exposed to these advertisements.

When examining the influence of advertisements in stores, the team found that middle school students exposed to them were twice as likely to use e-cigarettes than their peers and high school students were 91 percent more likely to use them.

"Advertising is thought to make product use seem more normative and acceptable, and to convey the impression that positive outcomes like having fun or feeling attractive will result from use," said William Shadel, a senior behavioral scientist at the RAND Corporation in Pittsburgh, who was not involved with the study. "It's possible, then, that exposure to e-cigarette ads promote thoughts that use is more prevalent and that using the product will result in positive outcomes."

The findings were published online in the April 25 issue of Pediatrics.