Non-smokers hate being around cigarette smoke. It aggravates allergies, stings eyes, smells awful and lingers in the air for what feels like an eternity. E-cigarette vapour has a mild scent that lingers in the air for just a second or two before fading away permanently. It smells nothing like smoke. In most cases, you can’t smell e-cigarette vapour at all unless you are next to the person using the e-cigarette.