Don't shoot the messenger folks. I know an executive in their transportation operation and am simply giving you their view. If you don't believe me look at their trucking operations. They are three years ahead of their aviation operation with trucking and last year they sent a shot across the bow of freight brokers that they intend to disrupt that industry. They will haul freight on their trucks for others because they have the capacity. They frequently move trucks near empty in order to make deliveries to their customers on time. They can use that empty space to move freight for a much cheaper price than brokers, just to lower their costs. They openly said they didn't care if it was profitable but that it lowered costs per package. They will do the same with overnight shipping once they have the capacity.
Fedex and UPS will be targeted by Amazon.