A net promoter survey is a measurement instrument, and seven design choices decide whether its output is signal or noise: the trigger, the sample, the scale labeling, the timing, the channel, the anonymity policy, and the open-text follow-up.

An NPS survey is a two-part customer feedback survey that measures loyalty by asking one rating question — "How likely are you to recommend us to a friend or colleague?" on a 0–10 scale — followed by one open-ended question asking why.