As e-commerce sales hit $513 billion, nearly 10% of total retail, in 2018, parcel expenditures rose 8.7% to $105 billion. Amazon is training customers to expect ever-faster deliveries, forcing competitors to chase those expectations, while at the same time growing its own transportation network and entering the third-party logistics business. This is sparking a furious pace of last-mile innovation, partnerships, and new technology.