Flexible Payment Plan
We want to setup service where client have to pay what they have consumed at end of every month. The current service/billing only support fixed amount of billing and we cannot offer enough flexibility in usage base payment.
For instance we resell Google Apps to customer and client have to pay for their active user every month. Right now we have to check Google billing system every month and have to do manual adjustment in customer invoice. There should be an option for some flexible payment system.
Other people can also share their input how they are managing this kind of services if they offer any.