These days, almost all legal nicotine purchases are sold in brick & mortar stores. Vape shops, tobacconists and convenience stores account for most sales of tobacco products. States have strong regulations on how nicotine sales are transacted and perform enforcement actions regularly. Many States receive excise taxes and other revenue from nicotine sales to fund these operations.
Most local vape shops have age-restricted entry, either by store policy or local laws. Convenience, gas and some liquor stores, unfortunately, do not enforce age-restricted entry policies. New laws, including raising the age to buy nicotine products to 21, have made a significant impact in the past 2 years.
Local jurisdictions could also implement a “Seed-to-Sale” style system utilized by the cannabis industry in many states. Very few licensed tobacco retailers or tobacco companies are willing to jeopardize their license by selling to minors.