Joel Spolsky - Seven steps to remarkable customer service:

"We treat each tech support call like the NTSB treats airliner crashes. Every time a plane crashes, they send out investigators, figure out what happened, and then figure out a new policy to prevent that particular problem from ever happening again. It’s worked so well for aviation safety that the very, very rare airliner crashes we still get in the US are always very unusual, one-off situations."