Based on practical experience, NPS is garbage because:
1) Even with stable mean and median, NPS tends to vary month over month, at least for my B2B settings where samples are probably much smaller than for B2C. Then, management goes nuts because of very subtle shifts in the distribution caused by NPS' arbitrary aggregation into promoters, neutrals, detractors. Of course, often investors are married to NPS, so educating management does not solve the problem.
2) NPS varies unreasonably across cultures. We used to say, somewhat tongue-in-cheek, that NPS is a US-centric metric, where things are either amazing or awful (with little space in between). E.g., in northern/central Europe, an 8 can be pretty amazing.
1) Even with stable mean and median, NPS tends to vary month over month, at least for my B2B settings where samples are probably much smaller than for B2C. Then, management goes nuts because of very subtle shifts in the distribution caused by NPS' arbitrary aggregation into promoters, neutrals, detractors. Of course, often investors are married to NPS, so educating management does not solve the problem.
2) NPS varies unreasonably across cultures. We used to say, somewhat tongue-in-cheek, that NPS is a US-centric metric, where things are either amazing or awful (with little space in between). E.g., in northern/central Europe, an 8 can be pretty amazing.