What changed
"Similar subreddits" is now computed two independent ways:
- By content — communities whose posts discuss the same things, from vector embeddings of what's actually posted.
- By audience — communities that share real commenters. Prowlo rolls up commenter activity (hashed, so no individual is tracked) and recomputes the overlap weekly.
Alongside this, subreddit stats now keep snapshot history: instead of a single overwritten number, subscriber and activity figures are recorded over time, refreshed on a tiered cadence — big, fast-moving communities update most often.
Why it matters
Content similarity finds communities that talk alike; audience overlap finds communities your actual audience moves between — often niche subreddits a topic model would never surface. Together they answer "where else are my people?" with evidence rather than guesses. And snapshot history means growth and decline become visible, not just current size.
How to use it
The Similar Subreddits tool shows both lists side by side for any community, free. The same data feeds watcher suggestions when you're choosing what to watch, and Subreddit Stats reflects the fresher numbers.