Media starts

The Media starts metric counts every media session that began. It is incremented as soon as the backend receives a session start event, even if the viewer drops out during pre-roll ads, buffering, or before any main content plays. Use it as the broadest top-of-funnel metric for media reporting; pair it with Content starts to measure ad and buffer drop-off.

How this metric is calculated

The media backend sets this flag when a session start event is received. The reported metric is 1 per session. Media starts is reported on the start call, not the close call; it is the only metric that does not wait for session close. All other media metrics, including Content starts, Content time spent, and Progress markers, are reported on the close call and are not available in real time during playback. Ad starts is the one additional metric reported on its triggering event rather than at close.