Why, despite rapid growth, was the air express industry characterized by low returns during much of the 1980s?

Why did competitive intensity moderate and prices rise during the late 1980s and much of the 1990s?

How the nature of the industry's offerings change during the late 1990s and 2000s? How has this impacted the intensity of competition in the industry?

Why do you think Amazon is expanding its operations in the industry? How big do you think Amazon's ambitions are? What are the implications for FedEx and UPS?