Discounts apply to wine shipments, letters, documents and promotional materials. Wine Institute has been the driving force in acquiring the current twelve reciprocity states. The three-tier distribution system was initially designed to prevent corruption in the production and sales of alcoholic beverages. A retailer would not be able to be unduly influenced by an alcohol beverage producer if the retailer's source for product is the wholesaler. Three-tier distribution establishes a system for revenue control.
States have an interest in collecting excise and sales taxes.
Three-tier distribution has, over the years, become as much a creature of politics as it is one of temperance and revenue.