What a snapshot is
Each point in the sparkline is a snapshot row: a single numeric read of a paired account at a specific timestamp. One user can produce many snapshots per day. Snapshots are bucketed by UTC day for the chart, regardless of where the user is.
Why the early shape is sparse
Throttle is in early collection. Expect bursty patterns: long flat stretches, sudden spikes when a single power user runs the extension all day. The sparkline is descriptive, not predictive — it shows what was measured, not what is typical.
What the 24h tile means
Snapshots in the last rolling 24 hours, not the current UTC day. It is the most sensitive freshness signal on the page: if it drops to zero for an extended period, ingestion is degraded.
What 'research opt-in' counts
Profiles that have explicitly toggled research participation on. All numbers on /stats aggregate every snapshot regardless of opt-in (they are anonymized counts). Future field notes that analyze patterns derived from snapshots will only use opt-in data.