Net Promoter® NPS®, NPS Prism®, and the NPS-related emoticons are registered trademarks of Bain & Company, Inc., Satmetrix Systems, Inc., and Fred Reichheld. Net Promoter Score™ and Net Promoter System™ are service marks of Bain & Company, Inc., and Fred Reichheld.
I have never been dissatisfied with the quality of their service. The last time I was in, they were honest in telling me they couldn't help as a friend had erased the fault codes.