Nicotine is one of the direct tobacco smoking byproducts. It is absorbed in the blood every time you breathe in and starts a real vicious circle: nicotine leaves your body very quickly, so it sucks for the next cigarette.
Nicotine salt is a natural state in which nicotine is in while in tobacco leaves. The nicotine salt needs a higher temperature to evaporate and the ions are not easily transported to the nicotine receptors in our body.
Higher levels of nicotine and instant nicotine salt acceleration help in smoking cessation. Some can argue that nicotine salts want more effective combat.