US Postal not seeing value to sponsorship... why?

gwhite wrote:

If they've driven out the competitors, and no substitutes
exist, they can charge whatever they want.

Not right -- only if demand is inelastic.

"What the market will bear"
is a competition condition, not the monopoly one you just described.

Not quite right. If demand is elastic, then some buyers could just opt out at higher prices, even
if there is no real close substitute. The monopoly firm would try to maximize profit, so there will
still be some aspect of the market driving prices (prices will be higher than a competitive market).
However, the overall quantity produced for society would be reduced, as some consumers got removed
from the monopolized market with its higher prices.

TK wrote:
... and then provide mail service at what the market would
bear rather than what the cost of delivery is.

The market for mail is monopolized by decree now -- meaning (by your take) that the Post Office is
"overcharging" if they make a profit, and representing a mandated wealth transfer (socialism) if
they lose money on first class mail delivery. It is simply easier, less prone to error,
non-elitest, and not building up the government Leviathan, if the market is simply allowed to adjust
by itself. And again, "what the cost of delivery is" is marxist, and doesn't exist in the current
situation anyway. It is unreal in concept, because no one could have the slightest idea of what
"true costs are" in an environment with distorted incentives.