The first time J. Andries Verleur tried an e-cigarette in 2008, he burned his lip and accidentally inhaled the nicotine fluid. “It was one of the worst products I ever tried,” he recalls, “but the idea was amazing.”

Verleur, a heavy smoker, was living in Prague and happened to spot the strange new product in a Vietnamese grocery store. The crude early version obviously didn’t work very well, but Verleur, a serial entrepreneur, immediately realized that if it did work, it could upend the tobacco industry. That was worth looking into: Cigarettes are a global business that generates more than half a trillion dollars every year, according to data from Euromonitor International.

In its simplest form, an e-cigarette is a cartridge filled with a nicotine solution and a battery powering a coil that heats the solution into vapor, which one sucks in and exhales like smoke. Typically, it looks like a regular cigarette, except the tip, embedded with an LED, often glows blue instead of red. The active ingredient in e-cigarettes is the same nicotine found in cigarettes and nicotine patches.