Satmetrix provided us with Net Promoter Score (NPS() certification. Our company uses NPS as a means of measuring customer satisfaction/loyalty in quarterly client surveys. The main benefit provided by Satmetrix is expertise on the NPS methodology.
Ironically, I found the customer support to be wanting. I regularly emailed them regarding an issue with my certification and it wasn't resolved for 6 months. More so, my emails were not returned in a timely manner and, at least once, not at all.
Some of the concepts taught are more abstract/subjective; having an official Satmetrix resource for questions (as opposed to the user community) would be welcome.
It is certainly well suited for anyone who has no prior experience in customer satisfaction surveys. Also, the concepts are mostly reinforced by examples of business to consumer transactions/relationships. If you are looking to implement NPS for measuring business to business customer sentiment the documentation glosses over a lot of the more challenging questions.