I always treat my customers/clients the way I would want to be treated, and it always seems to work out for the best. I've also given refunds to some customers without them asking for it first because I value their satisfaction more than I value a few dollars. There's no way to know for sure, but I suspect treating customers like this (like humans) increases retention and well-being, and not only for them, but for me (and my company) as well. It's called the golden rule for a reason. :)