A complaint is a gift - Janelle Barlow

Customer complaints can give businesses a wake-up call when they're not achieving their fundamental purpose--meeting customer needs.
They are a feedback mechanism that can help organizations rapidly and inexpensively shift products, service, style, and market focus.
Businesses that don't value their customers' complaints suffer from costly, negative word-of-mouth advertising.
Presenting dozens of real-life striking examples of poor--and excellent-- complaint handling, Barlow and Moller show that companies must view complaints as gifts if they are to have loyal customers.