> that statement would only be valid if e-cigarette had zero net impact in smoking adoption As a minor point, it could still apply with a slight overall increa

> that statement would only be valid if e-cigarette had zero net impact in smoking adoption As a minor point, it could still apply with a slight overall increase of use. The required scale is far closer to zero than what it actually was, but of how many new people vaping would you accept if it suddenly caused all smokers to never smoke. It's an interesting question of which is the best for public health.