Net Promoter Score has been and continues to be, one of the most trusted metrics used by brands to measure the health of customer relationships for 15 years. Many experts touted it as the one number you need to know when planning growth. Traditionally under the purview of customer experience and customer success teams, NPS has become the go-to metric for customer ranking.
https://thenextweb.com/contributors/2018/01/09/use-net-promoter-score-get-actionable-insights/