Core Vitals

## Summary

Umbrella epic for Open Library's three self-reinforcing product metrics — **Content Value**, **Retention**, and **Participation** — that together form a unified "Value Loop" for measuring and improving patron value. Each score previously tracked as its own independent epic; consolidated here so the three are visibly one system rather than three unrelated efforts.

```
Content Value (record quality)
→ higher-quality records lead to →
Retention (user engagement)
→ engaged users are inspired to →
Participation (community contribution)
→ active contributions directly result in →
Content Value
```

## 2026 priority: sequential, not parallel

Retention → Participation is the actual 2026 push. **Content Value is measured this year, not grown** — instrumenting and scoring the existing catalog as a diagnostic (identifying high-demand/low-usefulness records) — actively growing content value at scale is a 2027 goal. Participation also structurally depends on Retention working first (an engaged, returning patron is a prerequisite for a contributing one).

## Sub-issues

- [ ] #11954 — Usefulness & Demand Scores (Content Value)
- [ ] #11955 — Participation Score
- [ ] #11956 — Retention Score

## Stakeholders

* @mekarpeles
* @cdrini