I've always thought that the people who gave a damn were the ones who instinctively understood that energy given is not energy given away. It's energy given and kept.
Those who appear to not give a damn are the ones who think that if you expend energy on your customers, you lose that energy and become weaker. Ironically, they become weaker by not expending that energy.
A programmer going the extra mile by writing great customer facing software is like lighting a candle lighting another candle. At the moment they touch, both become brighter and then you have twice the light.
Thanks for the great examples. I love Zappos and hipmunk, too.