Suppose you need to deliver 40 terabytes of data to your co-workers in Atlanta (200 km). You have an available 100 Mbps dedicate
d link for data transfer. Alternatively, your friend raises homing pigeons and would be willing to let you borrow one. You have a single 1 TB SD card you can strap to the pigeon. Assume pigeons can fly 1000 km per day and that it takes no time to copy to/from the SD card.