The way around it, I think, is to set expectations early and often. If you’re going to give me your phone number, you better answer it. If you’re going to offer a warranty, you better honor it. If you position yourself as a company with real people eager to make every single person happy–you better deliver.
No matter what, you should decide. In advance. How much do you want to spend on ad hoc emergencies, how much do you want to reserve on design and helping the masses improve their experience?
Setting expectations? Amen to that!