To be truthful, the other things (combined) in cigarettes addicted the smoker. The nicotine wasn't the addictive chemical in the equation. There is still no definitive thing that can be pointed towards but the MAOI's in tobacco could be the major culprit.
Nicotine that we use in ecigs, do not contain the MAOI's. That's why some have to use WTA to help them stay away from cigs. Nicotine, on its own is just not quite enough to help them quit smoking.
Robino, you missed the humor!