It improved the success rate for smoking cessation, reduced relapse rates and extended life expectancy
These numbers gave smokers a sense of how strong a cigarette was based on measurable chemical content
One can even learn about the possible side effects

The full list of authors of the report are: McNeill A, Brose LS, Calder R, Hitchman SC: Institute of Psychiatry, Psychology & Neuroscience, National Addiction Centre, Kings College London and UK Centre for Tobacco & Alcohol Studies Hajek P, McRobbie H (Chapters 9 and 10): Wolfson Institute of Preventive Medicine, Barts and The London School of Medicine and Dentistry Queen Mary, University of London and UK Centre for Tobacco & Alcohol Studies Implications of the evidence for policy and practice: Based on the findings of the evidence review PHE advises that: e-cigarettes have the potential to help smokers quit smoking, and the evidence indicates they carry a fraction of the risk of smoking cigarettes but are not risk free e-cigarettes potentially offer a wide reach, low-cost intervention to reduce smoking in more deprived groups in society where smoking is elevated, and we want to see this potential fully realised there is an opportunity for e-cigarettes to help tackle the high smoking rates among people with mental health problems, particularly in the context of creating smokefree mental health units the potential of e-cigarettes to help improve public health depends on the extent to which they can act as a route out of smoking for the countrys eight million tobacco users, without providing a route into smoking for children and non-smokers

Dual smoking versus non-smoking To examine the effects of dual smoking on normal morphology, an interaction term between cigarette and shisha indices was used (Table 4)
Similarly, most airlines prohibit vaping on board, with rare exceptions made at the captains discretion for devices that produce no visible vapor