I guess I&#x27;ve just been relying on Prime too much for the last year, but I wonder: is <i>Amazon</i> relying on USPS more often or are other sellers on Amazon&#x27;s site relying on USPS? I ask because, as an infrequent seller, Amazon&#x27;s shipping credit barely covers USPS First Class for the Standard Shipping option that most customers choose. I certainly can&#x27;t afford to lose money shipping on UPS&#x27;s slowest&#x2F;cheapest offering instead.