Substack · Strategy · Mid · 45 to 60 minutes

Where should Substack deepen recommendations?

Substack is a platform where writers publish newsletters and other content, and readers can subscribe for free or pay. Answer this product management case and get it graded line by line against a weighted rubric.

Product strategy
Growth thinking
Metric design
Trade off judgment
Experimentation

The situation

You are a PM on Substack's growth team. The Head of Product asks you for a strategy on the next phase of Recommendations, a feature that lets writers endorse other writers and helps readers discover newsletters. The current system appears important enough that leadership wants to invest more, especially as the app and recommendation network become larger parts of reader acquisition. The question is where to place the next bet. One camp wants to deepen discovery inside the subscribe journey, where reader intent is high. Another wants to improve standalone discovery surfaces and ranking first, arguing that any added friction in a subscription flow could hurt conversion and feel pushy. A third concern is trust: Substack's brand depends on creator voice and reader choice, so growth tactics that look too centralized or spammy could backfire. You need to recommend a product direction that can increase network driven growth for both free and paid subscriptions while protecting conversion, creator trust, and product simplicity across web and app.

What to produce

Write a 1 to 2 page strategy memo.

Your answer must

Frame the core problem, target users, and why this matters now for Substack's growth model.
Present 2 to 3 strategic options for improving recommendations, with pros, cons, and a clear recommendation.
Define success metrics and guardrails, including effects on new subscriptions, paid conversion, and trust or quality.
Explain how recommendations should be sourced, including the role of creator endorsements versus centralized ranking.
Outline an experiment or rollout plan, key risks, and how you would learn quickly if you are wrong.

Constraints

Stay within existing Substack product surfaces and flows, across web and app, with no new marketing channels or partnerships.
Do not assume a large manual curation or moderation team can hand tune recommendations.
Any proposal must protect reader trust and must not materially worsen the core subscribe conversion flow.

Format

Use sections for problem, options, recommendation, metrics, and rollout.

How Substack actually played it

Substack reports that its Recommendations feature, together with the app, drives about half of all new subscriptions and a quarter of new paid subscriptions, then describes the next version, which bundles people to follow and publications to subscribe to into the subscribe flow. It shows how a growth loop built on peer endorsement was extended once it proved itself. Good for a PM studying network-driven growth features.

Report the share of growth a feature drives, since it justifies further investment.
Put the recommendation at the moment of highest intent, the subscribe flow.
Let trusted creators curate instead of relying only on centralised ranking.
Extend a working loop by packaging more value into the same step.

Built from Upgrading Substack's recommendation network by Hamish McKenzie and Sachin Monga, Substack.