In 2010, e-cigarettes looked like they could be a promising technology for tobacco companies and health advocates alike.

NJOY and Blu were the best known brands in the $144.7 million market, selling products that looked like cigarettes but produced a vapor. The e-cigarettes were received with cautious optimism by some in the public health field, who believed that they could give adult smokers a way to consume nicotine in a less harmful way.

“My view was that we were a technology company,” said Craig Weiss, who joined NJOY as president in 2010 and left as executive chairman in 2014. [...]