Or how nasal snuff is the cheapest tobacco per daily nicotine consumption but the most expensive by weight (ignoring high end cigars). The evidence of this is how small a pinch of oral or nasal tobacco is compared to smoking the same amount in a pipe.Nicotine is much more readily absorbed through mucous membranes (ie oral or nasal) rather than if swallowed
Hence with nicotine gum, you're told to chew a bit, then park the gum in your cheek. Then repeat
And not to chew like you're chewing gum and swallow.