UPS rules business shipping. Don’t know if Amazon is going after that.
I’m curious where Walmart stands. Although they’re not in the package delivery business, AFAIK they have thousands of empty back hauls a day other than occasionally returning trailer loads of pallets.
I’ve thought UPS would be a good fit for Walmart except for the union. FedEx given the reliance on subcontracting isn’t. Walmart needs to move beyond customers picking up internet orders at stores.