Hmmm, if you take a brick and mortar store, they have fixed costs to renovate and decorate the store, and they likely have capacity of the store that is not used during non-peak period as well. They charge for item sold, to cover for all costs they incurred for capacity of the store even during non-peak period as well. Is this an equivalent comparison? Don’t businesses generally roll in the fixed costs into their price and charge per unit still?