Entry, Exit, and Supply Curves: Constant Costs

Some industries have a flat supply curve. These are called constant cost industries. Take domain name registration: to increase the supply of domain names, we must only increase the inputs by a negligible amount. That is why even as the Internet expands so rapidly, it still costs only about six or seven dollars to register a new domain name. By showing you how these industries respond to an increase in demand, we can explain why they are constant cost industries.