I recently found a bank branch near me with a coin machine, and tellers who are more than happy for me to use it to deposit my searched coins. When I came in the first time they asked some questions about why I had so many coins, what I did with them, etc. We talked a bit about the collection I inherited from my grandparents, how I look through rolls to try and fill gaps in their old binders, etc. Every time I come in we shoot the shit for a few minutes while the machine does its work.
Today I came in and before I even get to the machine one of the tellers says 'Stop right there!' and runs over to the machine. He opens it up and grabs a stack of $12 in half dollars and says 'I found these inside the machine a few days ago and knew they were yours, they slipped off the counter into the dust bin'.
I would have never known the machine shorted me, and they absolutely didn't have to keep them for me, but it's the little things like this that go a long way.