I did quit smoking (completely) by using the ecig. I enjoyed the ecig for a couple of years, actually, without even considering giving it up altogether. It was almost instantly less addictive to me than tobacco, as I could go without the morning smoke (in the garage with the fan at the window), as well as put the ecig aside for a week without a thought. Finally, this past spring, I had oral surgery and I couldn't do the inhaling with the ecig, and when I did cheat and do this, it made my surgical site irritated. So I've given up the last vestige of my smoking addiction: the ecig. I will add that I had tried quitting smoking for years, and this is the only thing that worked. It's not perfect, of course, and not as safe as it's touted to be, but still far less toxic than tobacco with all the carcinogens.
Here's an article:
10 Things E-Cigarettes Won't Tell You - WSJ.com