Pitched as the one number you need to grow your business the Net Promoter Score (NPS) gives you a way to measure across your customer-base how many people love what you’re doing enough to tell their friends vs how many people are ambivalent or negative about your business. The resulting number, your NPS, from +100 to -100 has been shown to give a reliable indicator of companies’ future success.
To calculate your NPS ask your customers how likely they would be to recommend your business to a friend — or variations thereof — and give them a scale of 0 (not likely) to 10 (very likely) to answer on. Those who answer 9 or 10 are your biggest fans or Promoters. Those who answer 7 or 8 are passively satisfied — they like your business but are unlikely to shout about it. And anyone 6 or below are your detractors. If they talk about your business it could well be negative. Your NPS is your % of promoters minus the % of your detractors. For example, if you got 100 responses, 35 9s or 10s, 37 7s and 8s, and 28 0–6s then your NPS would be 35 minus 28 = 7.
Keep track over time and you’ll get a good sense of how your business is doing. Follow up with qualitative feedback, for instance “why did you give this rating?”, and get a recipe for improving your business. Simples.
Learn more in the original Harvard Business Review article, “The One Number You Need to Grow” by Frederick F. Reichheld.