complementary goods

Definitions

Economics

  • plural noun two goods which are consumed at the same time, such as frankfurters and rolls, so that the demand for one will increase if the price of the other falls. This is the opposite of substitute goods where the goods can replace each other and a rise in the price of one will increase demand for the other.

Marketing

  • plural noun a product for which demand is dependent on the demand for another product
http://www.dictionarycentral.com/definition/complementary-goods.html