Customer satisfaction - the Xerox Effect

Thanks to Martin Widlake for pointing to this gem of a paper from Dennis Adams (pdf), pointing out that an increase in customer satisfaction can lead to an increase in negative feedback, and vice versa. Anyone who has worked in customer support (whether on an internal help desk or for external customers) will have gone through a "why don't they love us, we're doing such a great job for them?" period. This might explain why.