A service provided to a customer is measurable in quantifiable service units used thereby such that billing to the customer is based on a number of the service units used. The customer obtains service unit credits to be applied against service units used, and the service is billed according to a billing cycle. For each billing cycle, service unit credits obtained and extant are applied against the service units used during the billing cycle. Service unit credits remaining after such application are carried forward to be available during a subsequent billing cycle. The customer is allowed to treat service unit credits as a commodity, whereby the commoditized service unit credits may be bought, sold, and/or traded for services and/or goods.