Lorillard has said it spent $40 million last year marketing Blu, mostly on TV ads. Mr. Bannon said the company planned to keep spending at about that level in the near term. The ads have paid off, but only to an extent. Sales of Blu hit $54 million in the fourth quarter of last year, but slipped to $51 million in the first quarter. Part of that might reflect changing consumer tastes, including the emergence of new e-cigarette technology, called tank systems, which present an alternative to e-cigarettes.

Sales of e-cigarettes are minuscule compared with Lorillard’s overall annual sales of $7 billion. Of that, Lorillard’s profit was around $1.2 billion, while the profit from e-cigarettes was just $6 million, raising questions of why tobacco companies are pushing so aggressively into the new market.

Mr. Bannon of Lorillard said the company saw two reasons to invest in e-cigarettes: first, as an insurance policy in case e-cigarette sales took off, and second, as a self-funding source of research and development into e-cigarette technology.

Such assurances aside, critics of the tobacco industry are wary.

“You’ve got to be extremely skeptical about what they’re up to,” said Gregg Haifley, director of federal relations for the American Cancer Society. Tobacco companies are not interested in getting people to quit smoking, he said. “They’re just too profitable for them to be interested in doing that.”

Mr. Haifley also warned that unfettered marketing of e-cigarettes would allow the tobacco companies to define the activity of smoking an e-cigarette as “sexy, youthful and vigorous,” and that in doing so, they may drive people back to cigarettes, their main market. And that, he said, would be a big setback for public health.

“To the extent that we’ve de-normalized cigarettes,” Mr. Haifley said, “e-cigarettes are undercutting that de-normalization.”

Bonnie Herzog, a financial analyst who covers the tobacco industry for Wells Fargo Securities, and who projects growth for e-cigarettes, said that the companies had big money to spend on marketing and that they had enormous influence over what kinds of products got carried in convenience stores. Ms. Herzog said the Big Tobacco companies also got a lift over smaller e-cigarette companies from the recently proposed federal regulations. The regulations, which the F.D.A. says may evolve, require disclosure about e-cigarette ingredients and manufacturing but don’t restrict marketing, favoring companies that have money to spend.