As an ISV, moving your application into the Cloud and offering it as a service is no trivial task. How software is supplied and managed for the desktop is very different than as a service. The usage and requirements of network connectivity, scaling, authentication and authorization, as examples, are all subtly different from the Enterprise model.
Once you get past the foundation of how to supply your application as a service, you need to solve the additional problems of authorization and utilization; or “Who has access to what?” and “How much are they using?”