Big Brown continued its reign as America’s leading delivery business even as it slipped two spots, to No. 43, on this year’s list. UPS's revenues rose 3.1%, to $74.1 billion, in 2019, keeping it ahead of perennial rival FedEx. But another threat looms. While FedEx cut ties with Amazon, UPS has hitched its signature brown wagons to the retailer-rocket ship, relying on it for growth. Still unclear is how that alliance will fare as Amazon doubles down on a delivery network of its own. Though UPS will benefit from increasing demand for store-to-door package service amid the coronavirus pandemic, the shipper's new CEO, Carol Tomé, will have to keep an eye on what may turn out to be a tricky coopetition arrangement with mighty Amazon.