I own the licence for Canada for the franchise network. I have no association with the USPS. I'm not privy to the specific data that goes on in that network.
The only thing I know from interacting with my colleagues in the United States, including my counterpart who is the president in the U.S., is that it has been beneficial to both parties, and the program continues to expand. My general assumption is that if the program continues to expand, it is therefore beneficial for both parties and ultimately beneficial for the consumers involved.