Oh, one more thing- I often rein in my dad's tips when I feel he's overtipping (eg, 100 on a 4k hit). His response is usually, "I can make them happy by tipping them, as opposed to one more push on the machine". It's hard to argue with that. The EV part of me hates it, the part that recognizes we only have one life to live applauds it.
I wonder what it says about me when he hits something, I'm holding his money, he says "tip them 100" and I only give them 40?