Exit before video start (EBVS) counts the viewers who waited at least a moment during the startup phase and then voluntarily abandoned before the first frame ever played. It is one of the failure-family metrics named in CTA-2066 practice, and it captures impatience rather than breakage, which makes it distinct from a video start failure where playback terminated with a technical error. It is measured as a share of play attempts from player events, the session ending after play intent but before the first rendered frame without an error. EBVS is exactly the abandonment the Krishnan and Sitaraman startup-delay curve quantifies, where each second past about two seconds adds roughly 5.8 percentage points. Its catch is that it vanishes from the startup-time average, because a session that never reached a first frame has no startup time to record, so a fast median can hide a wall of impatient leavers, and EBVS must be read together with startup time and video start failure.
