Until 2006, the Postal Service was entirely self sufficient, with no debt and no need for taxpayer funding.
However, in 2006 Congress passed a law requiring the Postal Service to prefund future retiree's health benefits (75 years in advance), which costs $5.6 billion per year. By 2012, the Postal Service hit its $15 billion debt limit, directly because of this.
The Postal Service itself does not lose money, and does not require funding, because it sells postage-- mailing is not free. The insane policy that Congress has foisted on it does lose taxpayer money, by requiring it to do something as far as I know no other organization does or is required to do.
If you want to fix the budget deficit at the Post Office, simply get that law repealed.
[1] https://en.wikipedia.org/wiki/Postal_Service_Reform_Act_of_2...
> 'A movie theater chain recently analyzed their user data and discovered that 72% of their profits came from concessions, primarily from impulse purchases made by people who swore they "wouldn't buy anything."'
This combination of non-descript source, precise numbers, and 'quotes' looks like the usual bullshit one reads in self-help books. I conducted a quick online search but couldn't find any direct source for this claim (although the number might be in the right ballpark).