How long do you vape for to get the benefit/feeling of having one cigarette?
Ask 10 different vapers and you'll probably get 10 different answers. The quick and dirty answer is going to be "vape until you feel satisfied." If you start getting light headed, feeling like your heart is racing, or the beginnings of a headache, then you've probably vaped too much.
How long do you vape for to get the benefit/feeling of having one cigarette?