Why So Many Cars At Youngsville Post Office?

I stopped at the Youngsville Post Office today to check the PO Box, and it seemed like there was a disproportionate number of vehicles in the parking lot in relation to the number of customers in the building.

Why so many cars?  I'm not certain, but one thing I do know is that the personnel at the Youngsville Post Office are always so nice! Always a pleasant experience there for me!

(Youtube/99.9 KTDY)