In recent weeks, some of the best-selling U.S. e-cigarette companies, including closely held Mistic and White Cloud, announced that they would move production to new, highly automated U.S. factories that would enable them to track ingredients and quality more closely. As a fringe benefit, they even expect costs to be lower than in China, the country that invented the battery-powered cartridges that produce a nicotine-laced inhalable vapor.