What Happens to "Unused Data?"

Yield management (differential prices) always seems to make sense in markets for perishable goods, ranging from grocery store produce to airline seats to electricity or mobile data.  

The point is that a retailer often sells products that have no value past a certain point in time. Airline seats are worth “zero” when the plane takes off. Electricity not consumed and paid for by a customer is lost, as it cannot be stored.

The same is true for data capacity now used by customers in any block of time. What can be “rolled over” are usage rights.

But here's a funny look at what happens to unused data.