Much of this has to do with a public perception that e-cigs are better for you. A survey by the Partnership at Drugfree.org found that 80 percent of people who smoke e-cigarettes thought they were less harmful than traditional cigarettes. And as of 2011, the Centers for Disease Control and Prevention reports, one in five adult smokers had tried an e-cigarette. But the Food and Drug Administration has just begun the process to regulate e-cigarettes, and states on its website that there is not yet enough research to know their potential risks.

“To say that it’s less harmful is like saying it’s better to jump out of the 40th floor than the 100th floor of a building,” says Stacey Anderson, an assistant professor of social and behavioral science specializing in tobacco marketing at the University of California, San Francisco.

Anderson says that tobacco companies have been looking for a product to keep them on top and combat declining cigarette sales for decades. After some lukewarm forays into chewable tobacco, “[tobacco companies would have us believe that] e-cigarettes are looking very close to being the Holy Grail,” she says. It’s not just the nicotine, see, that makes smokers want to smoke—it’s the ritual. The lighting, the puffing, the flicking of the ash. And e-cigarettes are the closest approximation yet.

And so, since 2012, Big Tobacco has begun snapping up e-cigarette startups. All of the world’s five largest tobacco companies have by now invested in e-cigarettes in some way, making their own products, or acquiring other e-cig companies. In one such instance, Altria Group, Inc., maker of Marlboros, purchased Green Smoke in February. David Sylvia, a spokesperson for Altria, explained that the capabilities of Green Smoke as a technology company were important to add to the traditional tobacco company, which has been selling essentially the same cigarette for decades.

“This new e-vapor category is five-years-old,” he says. “You have a lot of companies in this space today that have never sold traditional tobacco products. So that shows a massive shift in innovation that is very different than anything we’ve seen in my 15 years here.”

Philip Morris International is taking a different tack, developing several products that are somewhere between an e-cigarette and a conventional one. One, which is currently in clinical trials and will be commercialized later this year, consists of a tobacco stick inserted into a heating mechanism which heats the tobacco just enough to create an inhalable aerosol, without actual combustion.

Tomasso di Giovanni, head of reduced-risk product communications for PMI, says he thinks there’s still a gap between e-cigarettes and the experience smokers get from a traditional cigarette. And that’s the place in which they can innovate, getting asymptotically closer to the ritual smokers seek, while hopefully creating a product that’s less harmful.