I do not use the Post Office often but today I had to mail something 'Priority' with Delivery Confirmation. I went to the main Post Office in my hometown of Montclair. The line was not long but moving at a snail pace. It seemed that the most mundane task would take forever and in between customers the agent left the window. It was around 5.25 pm by the time it was my turn. I was told my letter would not leave until tomorrow as the Priority and Express Mail were already processed. I mentioned that an item of the same type was picked up just a minute earlier.
I was informed that the cutoff time for these was 5:00 pm even though they were open until 7:00 pm.
To conclude I did not feel it was customer service that I experienced but rather dealing with functionaries. They looked utterly uninterested in what they were doing, not rude but looking bothered that they had to deal with the public.

Maybe we should let Starbucks run the front of the house at the USPS.

Fits right there with the 5 ways to tick off people that I wrote during Customer Service Week.