What is VAST and why does CTV advertising use it?
VAST (Video Ad Serving Template) is the IAB Tech Lab standard that defines how a video ad server communicates with a video player. In CTV advertising, when the ad server selects a winning bid and needs to deliver the creative, it sends a VAST tag — an XML document — to the CTV player. The VAST tag tells the player where to fetch the video file, how long the ad is, what tracking pixels to fire (impression, first quartile, midpoint, third quartile, complete), and whether the ad has a companion banner. VAST is the mechanism by which an ad creative stored on a CDN is retrieved and played within a CTV app. Without VAST, the CTV player would not know where the ad file is or how to track it.
What VAST versions are used in India CTV?
VAST 2.0 and VAST 3.0 have been the long-standing standard in India CTV. VAST 4.0 and 4.1 add support for server-side ad insertion (SSAI), mezzanine file references (allowing the publisher to transcode the creative server-side), and improved verification. India CTV publishers have varying VAST version support: JioHotstar supports VAST 3.0 and 4.0+; smaller publishers on Google Ad Manager may be limited to VAST 2.0 or 3.0. When submitting creatives to India publishers, confirm which VAST versions are supported — sending a VAST 4.0 tag to a publisher whose player only handles VAST 2.0 will result in no fill.
What are the most common VAST errors in India CTV campaigns?
The most frequent VAST errors in India CTV: (1) VAST error 303 — no ads available: the VAST tag returned an empty response (often because the ad server had no eligible creative for the targeting criteria or the impression). (2) VAST error 100 — XML parsing error: the VAST tag XML was malformed; often caused by special characters in the creative metadata. (3) VAST error 400 — media file not found: the video file URL in the VAST tag returned a 404, meaning the CDN link is broken or expired. (4) VAST error 403 — geo or IP blocked: the CDN serving the creative has geofenced the URL; the CTV device IP is blocked. Check VAST error logs in the ad server or DSP delivery reports — these error codes pinpoint where in the delivery chain the failure occurred.