The real asset you're building is trust.
And even though it's tempting to cut a corner here and there to boost profit per interaction, the real cost is huge.
No one will say anything, no one will put up a fuss, until one day, they're gone. Those extra few dollars you made with some fancy footwork have now cost you tens of thousands of dollars in lost value.
The opposite is clearly true: invest a nickel or a dime every chance you get, and the trust you earn pays for itself a hundred times over.