Also there are those who may, externally, say they'd like to quit, due to social/societal pressure, peer pressure basically, but they don't actually want to -- I was that way for a long time, thinking oh I have to quit, my husband and everyone in my family is a non-smoker... but I really didn't want to, as I finally faced up to, and just started telling anyone who had the nerve to ask me about it, no, I probably won't ever quit. If it hadn't been for having asthma, and the confluence of a) my own awareness of e-cigs, and b) the coldest winter in 30 yrs, I wouldn't have been terribly interested in quitting, so even if I'd tried them, I would have just gone back to smoking. There does need to be a truly internal motivation in order to do something of this nature, of this caliber -- ie, those sent to AA by the court do not generally stay sober after their count-mandated AA attendance is past -- it just doesn't work that way. Those with that internal motivation will voluntarily begin substituting vaping for smoking, and that's precisely the method that has worked for me twice, the gradual replacement of smoking by vaping (and it took just about a month, both times).
Andria