What guardrail metrics should Spotify track for Audiobooks

Problem Statement Description

Product context: Spotify is an audio streaming company; its products include music, podcasts, audiobooks, playlists, recommendations, creator tools, subscriptions, and ads.

Spotify is expanding Audiobooks within a broader audio ecosystem that already includes music, podcasts, ads, subscriptions, recommendations, and creator tools. The interview asks you to identify the guardrail metrics Spotify should track to ensure Audiobooks grows without harming the listener experience, creator ecosystem, monetization, or long-term retention.

Approach this as a metrics question, not a product design or strategy pitch. You should clarify what success metric Audiobooks may be optimizing for, then define the supporting guardrails that would help teams detect unintended negative effects across listeners, authors/publishers, platform economics, and adjacent Spotify surfaces.

The experience should consider:

- Clear metric definitions, including numerator, denominator, time window, and measurement unit

- Which user groups and cohorts matter, such as new audiobook listeners, existing music users, premium users, free users, creators, and publishers

- How Audiobooks may affect core Spotify behaviors like music listening, podcast consumption, session frequency, retention, and subscription value

- Creator-side guardrails around discoverability, earnings, catalog participation, and satisfaction

- Instrumentation needs across discovery, sampling, purchase/access, listening progress, completion, abandonment, and refunds or support issues

- Marketplace and monetization guardrails, including revenue quality, cannibalization, content costs, and promotional efficiency

- Quality and trust signals such as recommendation relevance, content availability, playback reliability, and complaint rates

- Decision usefulness: which metrics would trigger investigation, product changes, rollout pauses, or deeper segmentation

The goal is to demonstrate that you can choose practical guardrail metrics that protect Spotify’s broader platform while allowing the Audiobooks business to scale, and that you can explain how those metrics would be measured, monitored, and used in product decisions.