Then there are interactions like we had the other day. A long time customer of ours thought he'd detected a strange new vibration in his bike, and asked if I'd look at the bearings in his front wheel. We gave him a "loaner" wheel for a day or two, so he could keep riding while I looked into the problem, and also so he could see if the phenomenon was present with the other wheel or not.
Long story short, it turns out there really wasn't anything "new" happening, but other factors had conspired to make an existing vibration more pronounced. We talked about it, and agreed it wasn't worth worrying about and the wheel bearings were fine. When he asked what he owed, I told him it was covered under our "continuing care" policy... when you buy a bike from us, any labor under $20 is free... and swapping the wheel and tire fell comfortably into that. But the customer wouldn't take no for an answer and said he was going to get his wallet.
I didn't talk to him again, but a few minutes later, John, my boss, told me what had transpired... the guy had left John $50! So when lunch time arrived, one of our staff was sent out, and returned with a pile of burritos for us all, as well as a carton of ice cream and a big bottle of root beer. Burritos and root beer floats for everyone... it definitely made a hot summer day feel a lot cooler and more fun!
It's days and customers like that one that make the few tough times a lot more bearable. And makes you really appreciate being appreciated.