Define and Measure Product–Market Fit (PMF) for Alexa Shopping

Context

You are designing a measurement plan to assess PMF for Alexa Shopping, where customers can use voice to shop on Amazon. The plan must span metrics, instrumentation, identity, cohorting, seasonality controls, thresholds, longitudinal analysis, conflict resolution across signals, and causal validation of PMF drivers.

Task

Create a PMF metric framework and analysis plan that includes:

1. PMF definition and success criteria for Alexa Shopping.
2. Metric framework with:
   • Activation: first successful voice purchase with payment set up.
   • Engagement: weekly voice shopping intents per active household; voice share of total Amazon purchases.
   • Retention: W1, W4, W12 household retention on any voice shopping action.
   • Satisfaction: PMF survey (% extremely disappointed if removed); task success rate.
3. Event instrumentation: events, schemas, and properties needed to compute the metrics and diagnose friction.
4. Identity: household vs device identity, and how to deduplicate across devices and profiles.
5. Cohorting rules: cohort by first activation month and define analysis windows.
6. Seasonality controls: handling Prime Day and holidays to avoid false PMF signals.
7. Leading indicators: repeat purchase intent, saved reorder lists, and other precursors to durable use.
8. PMF thresholds: how you would set targets for each metric and interpret them.
9. Longitudinal cohort analysis: curve shapes to expect, diagnostics, and summaries to track.
10. Reconciling conflicting signals: for example, high survey PMF but low repeat usage.
11. Causal validation: experiments or causal inference to validate whether improvements in intent understanding drive PMF.