The problem is that it costs Skyangel a certain amount of money per subscriber per month to provide the service to the customer, reguardless if the customer is on a lifetime plan or on month to month.
When customers are paying a monthly bill, its easy to track because the customer is either paying and watching TV, or not paying and have cancelled the service.
When you have a lifetime subscription, you do not know if the customer still even has the service anymore. If the customer switches to Cable, moves, Dies or no longer wants the service anymore they do not call anyone to cancel. The service simply continues on and costs skyangel money each month to maintain.
The lifetime subscription option was a bad move, it did help pay the bills and keep the service viable in the early days, but as the lifetime subscriptions went on, and the market got saturated (Less new activations) The lifetime subscription became more of a burden to maintain.
I feel the post cards where a great idea to help weed out the customer base to see how many are still watching!