In traditional supply chains, products are stored in warehouses, and then shipped to the physical retail stores where customers can purchase products. For instance, this has been the traditional strategy of Barnes & Noble. However, with the rise of e-commerce (e.g., Amazon), many supply chains have eliminated physical retail stores, and started to ship out products directly from warehouses to customers. This strategy is called "direct shipping." What are the advantages and disadvantages of direct shipping over the traditional strategy with physical stores