An exchange is a department store on military bases. It provides a full range of quality merchandise and services at uniformly low prices to the military community regardless of where they are stationed throughout the world. Military exchanges are categorized as joint military activities. They are self-funded and pay operating costs from revenues. Exchanges return earnings to customers through payments to MWR activities and investments in new or renovated exchange facilities. Since exchanges receive only a limited amount of taxpayer dollars, they are listed as a nonappropriated (NAF) fund activity; that is they do not rely on taxpayer dollars. The subtle difference is that a different set of laws and regulations govern their internal operations. Exchange sales total more than $10 billion with over 3000 outlets worldwide.