Shows the maximum amount of time, that media are played. The value is accumulated over all views.
This metric is usually not directly used in analyses but for calculations in custom formulas.
A user watches a video for 30 seconds, rewinds it to before the 10-second mark of the video and watches another 20 seconds. The Run Time for this view is 30 seconds. Another user watches the same video for 10 seconds. The Run Time across these two views is 40 seconds (30+10).