What happens if the credit card that's tied to the cloud services account expires and no one within the company remembers to modify the account to use a current credit card? If this happens there is the possibility of a service disruption.
What happens when the credit card is good, but because of security protocols put in place by the credit card company they stop accepting payment requests from a certain vendor because they've seen too many of the same charges or same amount charged from a certain vendor (don't laugh, this happens more than you know).
What happens when the cloud vendor only allows a customer to tie one (1) credit card to an account? Why not have a backup credit card tied to that cloud account? Who would have imagined that you'd need a backup credit card for to cloud services.
Availability is a primary selling point of the Cloud. Make sure that the way your organization pays for the Cloud has backup.