Despite increased controversies over the health effects of electronic cigarettes (e-cigarettes), little is known about how the public interest issue has been discussed by e-cigarette companies on social media. Using arguments from the theory of planned behavior as a guide, this study examines how e-cigarette companies engage with potential customers on Twitter. Using quantitative content analysis, this study examined 525 tweets from the top five e-cigarette companies that occurred between July 9, 2016, and September 9, 2016, one month before and after the U.S Food and Drug Administration implemented a new regulation limiting sales and distribution of tobacco products to minors. Results indicate that the deeming did not affect e-cigarette companies’ message strategies on Twitter. Theoretical and practical applications for public interest communications are discussed.