The smaller the gesture, the greater its weight in determining how much the person behind that gesture values you.
My father once worked in a large office building for a software company. One of the perks at this job was that the soda machines in the break rooms didn’t charge for the soda. You could just go in there, hit a button, and have a Coke or whatever. Wholesale cans of soda probably run around a quarter apiece, so this wasn’t exactly breaking the bank for the software company. But the employees loved it, even though it maybe represented less than a few dollars per week of actual “benefit” to any given person.
One day the company was bought by a larger software company, and the new bosses changed the soda machines to charge standard retail prices, like 2 dollars per soda. The employees went berserk. There were mass walkoffs. My father told his new bosses why everyone was quitting, and they were flabbergasted. This was a few dollars a week difference. They couldn’t imagine why anyone would care so much.
But that’s the test. The less “valuable” the gesture is, the more you look like a complete asshole if you don’t do it.
If you get a $20 meal, the difference between tipping 10% and 20% is two dollars. That’s minor to you and, quite honestly, probably minor to the person you’re tipping. Which is why you should do it: it’s so minor that not doing it makes you a jerk.
Someone else I told this story to recently told me that his similar test of an employer’s value system is to see what kind of toilet paper they stock in the employee bathrooms. It’s not a huge price difference between the bad kind and something with some quality, but you buy far more goodwill by spending a pretty minor amount of money.
Small gestures that you don’t have to do are exactly the ones that carry the most weight. So don’t cheap out on the soda, the toilet paper, the small compliments, or the extra 10% on that tip. You’ll earn far more than you pay.