Any idea on how to setup USAGE BASED BILLING (for a telecom company) for Software as a service products? i.e Products like IP offices, virtual desktop's etc. the company would bill customers, based on the end usage. there may be a lot of change orders involved. i.e increase, decrease, discontinue etc. we need to be able to pro - ratedly bill the customer based on their needs. Any inputs would be very use ful to me..