A commentary notes some gaps in data: the analyses do not yet extend to investigating the distribution of effect among different population groups, particularly those with the highest smoking rates and don’t address other considerations, such as the long term safety of e-cigarettes. It adds that the study findings are not entirely novel as recent research from UK using a different methodology drew similar conclusions. Notably, both studies analysed data from populations in countries with relatively liberal regulatory approaches towards e-cigarettes. It adds that the current study suggests that where such permissive approaches to e-cigarettes exist—ones that enable smokers to have ready access to products that deliver nicotine effectively, at a price lower than that of tobacco cigarettes—then substantial numbers of smokers will make the transition away from smoking, and a substantial population benefit can result.