Subscriber retention by topic.
Built for Substack writers.
Substack tells you total subscriber count. We tell you which topics keep readers and which topics lose them. Cadence vs growth correlation, lapsed-reader cohort, weekly publication health report.
Subscriber retention by topic
See which post topics keep readers (and which lose them).
Tier: Indie ($9/mo)
Cadence vs growth correlation
Weekly cadence vs subscriber growth, per topic cluster.
Tier: Indie ($9/mo)
Benchmark against similar publications
Compare your retention curve to publications of similar size and topic.
Tier: Scale ($29/mo)
Auto topic cluster
Embed your posts and auto-cluster by topic, see retention per cluster.
Tier: Indie ($9/mo)
Lapsed-reader cohort export
Cohort of subscribers who stopped opening, export for win-back.
Tier: Scale ($29/mo)
Weekly publication health report
Weekly email summary, topic retention deltas, cadence health.
Tier: Indie ($9/mo)
Why topic retention
Substack default analytics shows total subscribers, open rate, and referrers. It does not show which post topics retain subscribers and which trigger unsubscribes. Writers end up guessing what works.
We embed your posts, cluster by topic, and correlate each topic cluster with subscriber delta in the week after publication. The result is a heatmap: which topics grow the list, which shrink it. You can plan the next 3 months by the data instead of by hunch.