In all the many and various ways of measuring customer satisfaction here is the one simple question that you should be asking ; ” How likely is it that you would recommend us to a friend or colleague? ”

It was obvious really, because we are more likely to tell it like it is to the people we care about. But it took some serious research by Bain & Co and Fred Reichheld the author of The Loyalty Effect to convince us that this is so.

This work underpins the metric called NPS – Net Promoter Score which is a simple and effective way to find out just how satisfied your customers really are.
Bain & Co explain why they call it the One Number to Grow here