In recent years many states in the United States have created a new class of winery license, the farm winery, to allow farms to produce and sell wines on site. Farm wineries differ from commercial wineries in that the fruit which is the source of the wine is usually produced on the farm, and the final product is also sold on the farm. States such as New York have given a special permit to open a satellite store in a tourist area. With New York's passing of the Farm Winery Law of 1976 an example was set for many other states to pass similar laws.
Farm wineries are usually at a much smaller scale than commercial ones. Farm wineries may produce distinctive and very high quality wines. There are highly competitive contests by which wineries can establish prestige by winning in their categories. Farm wineries are a form of value added marketing, also known as agritourism, for farmers who may otherwise be struggling to show a profit.
Source: French Wine