A package delivery company provides both overnight and second-day delivery services. It charges almost twice as much to deliver an overnight package to any world location as it does to deliver the same package to the same location in two days. Often, second-day packages arrive at company warehouses in destination cities by the next day, but drivers intentionally do not deliver these packages until the following day. What is this business practice called? Briefly summarize alternative perspectives concerning whether this activity should or should not be viewed as a form of price discrimination.