3. The vapor is drawn very slowly and gently into the mouth (not the lungs). A hard pull, as is normal with a cigarette, cannot be used since:
a. The heater coil doesn't work properly unless air is drawn across it gently for several seconds. There won't be any nicotine in the vapor if a short hard pull is used.
He/she seems to be saying you must draw for several seconds or there will be no nicotine in the vapour so short puffs are pretty much pointless unless you just want the flavour.