NPS (Net Promoter Score)

NPS formula: % Promoters - % Detractors = NPS Example: Survey 100 customers. 50 give you 9-10 (promoters), 30 give 7-8 (passives—ignored in calculation), 20 give 0-6 (detractors). NPS = 50% - 20% = +30. NPS ranges: -100 to +100. Negative NPS = more detractors than promoters (bad). 0 to +30 = okay, room for improvement. +30 to +50 = good. +50 to +70 = excellent. +70+ = world-class (rare—Apple, Tesla, Airbnb territory). Why NPS matters: It predicts growth. High NPS = strong word-of-mouth, low churn, organic growth. Low NPS = you're leaking customers faster than you acquire them. Investors care about NPS—it's a leading indicator of retention. The follow-up question: Don't just ask the score—ask 'Why?' Promoters tell you what to double down on. Detractors tell you what's broken. This qualitative feedback is more valuable than the score itself. When to measure NPS: Survey after key milestones: post-onboarding (did they see value?), quarterly for active users (are they still happy?), post-support interaction (how was help?), before renewal (will they churn?). Timing matters—surveying too early yields unreliable data. NPS limitations: (1) Cultural bias—Americans give higher scores than Europeans, (2) Survey fatigue—over-survey and response rates drop, (3) Doesn't explain *why*—you need follow-up questions, (4) Vanity metric if you don't act on it—measuring without improving is useless. Improving NPS: (1) Fix detractor issues first—address top complaints, (2) Amplify promoter drivers—do more of what makes people love you, (3) Close the loop—respond to every detractor personally, show you care, (4) Track NPS by cohort—are new customers happier or less happy than old ones?

Apple's NPS is ~70 (fanatic loyalty). Tesla's is ~90 (best-in-class). Most SaaS companies are +20 to +40. If you're below 0, you have serious product or service issues to fix immediately.