Ecigarettes Not a Gateway
According to results on English Ecig users, Ecigarettes got a clean bill of health, at least in terms of the theory that they could encourage our youth into smoking conventional cigarettes. No evidence could be found in the sample of young users to suggest ecigarettes were leading to smoking. Very few who had experimented took it up as a habit, at around 3%. This figure is much lower than with cigarettes so we can conclude that ecigarettes are not very addictive. Additionally none were never smokers, which strongly suggests that those using ecigarettes are simply switching from cigarettes.
See more here - Tobacco Analysis
Meanwhile, in America, an interesting article on Forbes (Why Is The CDC Lying About E-Cigarettes?) highlights similar findings in the US. The rates of teenager use of cigarettes and ecigs has been moving in opposite directions. We have to scratch ones head hard to see how this finding can be consistent with an e-cig 'gateway' effect.
The National Youth Tobacco Survey showed that smoking rates were falling amongst American High School students, whilst there has been a steep rise in middle school e-cigarette use. It appears then that more efforts are needed to discourage ecigarette use amongst the youth but at least it isn't leading to an increase in smoking, and appears to be replacing it.
While a consensus has not yet been reached on this contentious issue, the ecig industry should obviously still be adult-orientated to ensure it does not appeal to the young.