Time spent / session length
Depth of engagement; pairs with frequency.
- Formula
- Total minutes / sessions (or per day)
- Unit
- minutes
- Models
- Media, Gaming
| Messaging (WhatsApp-class) | ~35 min/day (illustrative) | a16z; GameAnalytics |
| Games / daily time | ~22 min/day (illustrative) | a16z; GameAnalytics |
| Games / session length | ~5–6 min/session (illustrative) | a16z; GameAnalytics |
What it is
Time spent / session length measures either average minutes per day per user or average minutes per session. It captures engagement depth — how long users stay, not just whether they showed up.
How to calculate it
For daily time: sum all session minutes in a period and divide by DAU. For session length: sum all session minutes and divide by total session count. Both can be computed from the same session-level event log.
Why it matters
For media and gaming products, time spent is often the primary revenue driver: ad-supported businesses monetise impressions, which scale with minutes. It also predicts skill development and social graph formation in games, and content consumption depth in media. Tracking session length alongside daily frequency reveals whether time-spent changes are driven by visit intensity or duration.
Benchmarks & pitfalls
All figures here are illustrative reference points only — sourcingTier is directional. A16z and GameAnalytics data suggest WhatsApp-class messaging at ~35 min/day; games at ~22 min/day with ~5–6 min per session. There are no published Good/Great bands for this metric. Be precise about whether you measure time as active-foreground time or total app-open time; background audio or video can inflate the latter. Comparing across categories (messaging vs. games vs. streaming) is rarely meaningful.