>> That is totally false.
Like Hell it is.
After rereading your original wording, I see that you are correct: the USPS derives REVENUES from sales, not from taxation. However, I think you were trying to claim that the USPS does not take money from the taxpayers, and this is COMPLETELY AND UTTERLY FALSE! The USPS has already stiffed the taxpayers on at least one loan and has lost more than $6B this year.