How do you justify post office buildings?

The Post Office is trying to figure how to branch out, and stem the tide of money losses.
One idea is doing payday lending.
Banks and lenders are wary.
But what are the post office's strengths?
They are everywhere.
People pick up their mail at the post office boxes daily or weekly.
While they are there, what else can they do?
Probably won't work, but at least they are thinking outside the post office box.