The subscription business moel is a business model that was pioneered by magazines and newspapers, but is now used by many businesses and websites. Rather than selling products individually, a subscription sells periodic (monthly or yearly or seasonal) use or access to a product or service, or, in the case of such non-profit organizations as opera companies or symphony orchestras, it sells tickets to the entire run of five to fifteen scheduled performances for an entire season. Thus, a one-time sale of a product can become a recurring sale and can build brand loyalty. It is used for anything where a user is tracked in both a subscribed, and an unsubscribed status. Membership fees to some types of organizations, such as trade unions, are also known as subscriptions.