market test

exposure of goods or services to a small sample of the entire market to test various marketing strategies. Some areas of the country are considered better barometers of demand than others, because the tastes of a particular area for certain products seem to resemble those of the whole country. These are most often areas that attract mobile people from all over the country, such as the Sunbelt states. The area chosen must be representative of the areas where that product is in demand. For example, swimwear would not be tested in North Dakota, nor snowshoes in Florida.

Some markets are used as the ultimate test of demand for a product, because consumers there are slow to accept a new brand or product. That's the meaning behind the theatrical phrase "Will it play in Peoria?"