The idea of a lifetime warranty.

Mission Repair recently released a lifetime warranty. I like the idea of a lifetime warranty. Kudos to them for not being afraid to advertise it.
The idea being, if you break your device again, you pay a reduced rate to have it repaired again instead of full price.
I've been doing this since 2008. However, I've been deathly afraid to advertise it, or to make it an official policy. People in New York City have a tendency to, for lack of better word.... "take advantage", when something free is offered. I love the city and I love the people, but there are also times where I can't stand the city or its people.
I have plenty of nice, kind customers. I have lots of anxious, worried customers. Lots of concerned customers. 99% of them are an absolute joy, I see them again just to hang at the studio even if they're not having repairs done. Some even wound up becoming business partners in other ventures. I like the people aspect of this business more than anything else. I like going out to meet people at their homes and offices to repair their devices. I like the personal touch. If my life were confined to a bench and an assembly line of repairs, I'd most certainly go find a more rewarding profession.
I also have lots of vile customers who are god damn livid that I am charging them $140 to replace the cracked LCD on their computer. People who yell every step of the way, people who aren't at their homes when myself or my assistant show up for a house call. Why should I give someone who wastes hours of my time the courtesy of future free work?
I like to pick and choose the people whom I will perform work again for, for no extra $. For most people, I don't mind and enjoy keeping them happy. For the repairs that take an hour or two, if it's someone who presents an exceptional challenge to work with due to stupidity, their own anger, etc, then doing work again for free if it's not a warranty issue, isn't desireable.