| name | pmf-leading-indicator-assessment |
| description | Evaluate product-market fit using the Sean Ellis Test. Use this skill when you have a live MVP and need a leading indicator of fit before investing in growth, when retention is low and you need to diagnose the cause, or when you need to identify your "must-have" user segment to refine positioning. |
The Sean Ellis Test (or "The 40% Test") provides a leading indicator of product-market fit. While retention cohorts are the ultimate "lagging" proof of fit, this survey allows you to identify if you have a "must-have" product day one, without waiting months for data to mature.
1. Segment the Audience
Do not survey everyone. Surveying people who have only seen a demo or just signed up will result in "noise."
- Target: Users who have experienced the "core" of the product.
- Criteria: Must have used the product at least twice.
- Recency: Must have used the product within the last 1–2 weeks (active users, not churned users).
- Sample Size: Aim for at least 30–50 responses for valid initial signal.
2. Deploy the Primary Question
Ask the single most important question to gauge "must-have" status:
"How would you feel if you could no longer use [Product Name]?"
- Very disappointed (The "Must-Have" group)
- Somewhat disappointed (The "Nice-to-Have" group)
- Not disappointed
- N/A – I no longer use the product
3. Analyze the Threshold
- 40% or higher "Very Disappointed": You have found a "must-have" vein. You are ready to focus on activation and sustainable growth.
- Below 40%: You are likely in a "commodity" state or targeting the wrong segment. Do not scale marketing yet; you will waste capital.
