FWIW: When I worked for the AA I was taxed on the expectation of receiving tips. It cost me approx £5 a week in extra tax. I made a lot more than this in tips, as I would go the extra mile in the service I gave. This is why I give tips. Someone goes the extra mile for me. I tip.
I think I understand what you are saying but it's the extra mile that is the difficult part to pin down.
At the risk of sounding conceited, I know I was doing more (for the customer) than others performing the same function in different areas but that was the job as I saw it.
There was a pay off, because I would be back in the same area in the future, I found the word had got around, and next time in that neighbourhood, people would be helpful rather than obstructive.
It worked something like this;
Local; Hello Mr Meter Man, was it you that was at my friends he/she got £X00 back after they did as you said, what are you looking for today?
Me; Oh good for them, I'm looking for this address but somebody's moved it!
Local; Oh you'll never find that, they were demolished 7 - 8 years ago and replaced by XXXXXX,
They all moved into YYYYYY apart from AAAAAA and they left but BBBB is in No 10, CCCC in 12 and so on.
Me; Well thank you, you have saved me half a day of hunting around.