All I know for sure is that, once I got down to 1 cigarette per day, I found it impossible to dispense with that 1, the morning smoke, until I paid attention to how I was inhaling it. I mouth-to-lung inhaled as a smoker, and I do the same now, but what I found was necessary was just slowing it down -- no short hard deep inhale, but a longer, slower draw, a longer, slower inhale, and letting a great deal of the exhalation come from my nose.
The satisfaction will not be immediate as it is with cigarettes, just because it takes longer with vapor than it did with smoke inhaled to the lungs, but if you are patient, you CAN get the same satisfaction, or at least enough of it to make abstaining from smoking FAR easier.
And it's true, you don't actually have to inhale vapor to the lungs at all, to get the nicotine, it's just that most of us are in the habit. Nothing wrong with inhaling to the lungs once you've let it hang around in the mouth and throat for a few seconds, but that mouth/throat exposure is necessary to get the max amount; exhaling via the nose is also an excellent way to get max nicotine.
Those doing direct lung inhales are probably using the type of cloud-making devices that deliver so much vapor and hence nicotine, that none of this is necessary, but most don't start out with that type of device.
Andria