Software as a Service (SaaS), a major trend in IT, turns the conventional use model for software on its head. In contrast to the conventional use model, which requires a software user to pay fees to acquire rights to use and upgrade a software package, SaaS bills users for the service, based on the number of users or duration of service, as with electricity or satellite TV. All parties to an SaaS agreement have the potential to benefit from this approach—the software (I mean service) provider receives a steady stream of monthly or annual revenue, and users get a centrally maintained, professionally managed, and reliable set of services, without the traditional overhead of having to install, maintain, and manage services themselves.