Most scholars agree that there are four characteristics that distinguish services from goods. These are:

• Intangibility: They cannot be touched tasted smelt or seen. There is also the difference in perception that that the service cannot be "owned" by the user but it is simply rendered by the provider.
• Inseparability: The act of being created requires the source, whether person or machine to be present. Production and consumption occur simultaneously with services.
• Heterogeneity: Services are difficult to standardise. Zithaml, Parasraman and Berry (1995) say: "Heterogeneity concerns the potential for high variability in the performance of services. The quality and essence of a service can vary from producer to producer, from customer to customer, and from day to day". Heterogeneity in service output is a particular problem for labour intensive services.
• Perishability: Services cannot be stored for future use. In the context of a call centre – if no calls are made to an operator for an hour then that hour of service is lost forever.