Just because you have an agreement to keep the service for 2 years, doesn't mean anyone will stay. The customer can still void their contract and leave- even if they don't pay. You're assuming the customer will pay and the carrier will still be paid in full. But if the carrier sells the debt to another outside company for collection, the carrier still won't get paid the full amount and it's up to that collection agency to get repaid. There is a LOT of IFs in that one and really doesn't prove anything on getting paid.