Daily Digit is the story behind the numbers that make our world work. Today, we're looking at the myth that switching to e-cigarettes is an effective way to quit smoking. New research shows that 90% of cigarette smokers who switch to vaping are still smoking a year later. Despite the manufacturers' claims that nicotine vapor offers a healthy alternative to cigarette smoke, there have been no definitive studies on the long-term health effects of inhaling the chemical ingredients of liquid nicotine. Last year, Juul Labs, the leading manufacturer of e-cigarettes, saw revenue increase by 787%, and the total market is expected to grow to $48 billion in the next five years.