Essay

Using Product/Market Fit to Drive Sustainable Growth

Sean Ellis · GrowthHackers Free Intermediate

Ellis lays out the 40 percent test, the survey question and threshold he found across hundreds of startups for knowing you have found a must-have product. It is a quantitative complement to the qualitative pattern recognition approach, a second, numeric way to check your gut sense. Run it once your interview pattern feels solid, as a sanity check.

• Ask users how they would feel if they could no longer use your product: very disappointed, somewhat, or not at all.
• Forty percent or more saying very disappointed is the benchmark tied to sustainable growth.
• Use this survey to confirm a pattern you already sense from interviews, not to replace talking to people.