Utility Model

The utility or "on-demand" model is based on metering usage, or a "pay as you go" approach. Unlike subscriber services, metered services are based on actual usage rates. Traditionally, metering has been used for essential services (e.g., electricity water, long-distance telephone services). Internet service providers (ISPs) in some parts of the world operate as utilities, charging customers for connection minutes, as opposed to the subscriber model common in the

U.S. Metered Usage -- measures and bills users based on actual usage of a service.

Metered Subscriptions -- allows subscribers to purchase access to content in metered portions (e.g., numbers of pages viewed). [Slashdot]