In the absence of a large-scale statistical study, it is difficult to answer this question exactly. We nevertheless estimate the current number of vapers at nearly 3 million … in France alone. The advisory offices of Ernst & Young LLP realised a comparative study of 7 countries in 2016 (France, UK, Germany, Italy, Poland, Russia, South Korea). They estimated the global accumulation of vapers in these countries was 5.1 million.
Finally, the National Health Interview Survey stated that in 2016, in the United States, 7.8 million adults had already used an electronic cigarette at least once.