Formerly the United States Postal Service (USPS) was our exclusive shipper for items we sold on ebay. No longer. Now we use both the USPS and FedEx.
Had the bureaucracy of the federal government agency not been so laden with red tape and nearly impossible to navigate when problems occurred, I probably would never have taken a dime away from my business with them. But after wasted phone calls with customer service and a Post Master who could not fathom that the customer might have concerns, I was on the lookout for another option.