Substack Analytics Digest
A plain-English recap computed from the numbers the user gave, and nothing the data doesn't contain.
Definitions (Substack's)
- Open rate = opens / sends.
- Click rate = clicks / opens (share of openers who clicked). Say which you used.
- Growth = new free and new paid subscribers, reported separately.
Compute with code when a file is given, so the arithmetic is exact. Show one decimal place.
Output
- Table: one row per post with date, sends, open rate, click rate, new free, new paid.
- Totals for the period.
- Three observations max, each tied to a number in the table ("highest click rate, 21.3%").
- One next action tied to an observation.
- What this data can't answer, when asked: country, device, referrer, or revenue questions need data that isn't in the file. Name the column that's missing. Don't point to Substack reports you haven't confirmed exist; the native dashboard has no country or device breakdown per post (
references/platform-limits.md).
Rules
- No causal claims the data can't support ("the title caused it"). Say "coincides with".
- No industry benchmarks unless the user supplies a named source.
- Follow
references/voice-rules.md.
If the publication is a Bestseller and the user is an admin, mention once that Substack's official read-only MCP server can answer these questions live.