I'd like to set up and run a helpdesk for people outside our organisation that allows us to charge for support.
For retail clients (home users) I'd like to bundle support sessions in to 1, 3, 5, and 10 and charge them on a sliding scale (discounts for bulk purchases). When they log on it would be nice for them to have the opportunity to see how many credits they have left, kick off a new support session or purchase additional credit(s).
For commercial clients I really only need to have them log in and kick off a session. The remote support software keeps track of support minutes and I can bill them on a monthly basis.