About VAST and VPAID Ad-Serving Methods

See also:


About video advertising

  • Video ads are not static but consist of a certain playtime, play at the same position on a web page like the video content, and can be more than one asset.
  • Video ads have special properties (play time, bit rate etc.) and can have different formats (Flash, MPEG etc.).
  • Instead of the browser now the video player controls the ad requests and the response from the ad server.
  • The ad server uses dedicated tags for video requests, and responds in a VAST or VAST+VPAID  compatible XML document that deliver a video ad within a video player.


Video Ad Request

A video ad request takes place when a user opens a website with a video that starts automatically or when the user starts to play a video, and the video player requests a creative from the ad server.


Video Terminology

The following table describes some frequently used terms when using VAST and VPAID ad-serving methods for video delivery: 




  • Creatives are media files with optional companion banners.
  • The companion properties are defined as part of the same creative object.
  • Click through URLs and third-party tracking beacons are also defined in the creative.

In-Stream Video Ads

Video Ads played before, during or after (pre-roll, mid-roll or post-roll) a website’s streaming video content, within the publisher’s video player. These ads cannot typically be stopped from being played. This format is the most frequent method publishers use to monetize their video content.

3rd Party VAST Creative

Creatives in Video SSP are managed under Campaigns > Creatives. As part of this set up, you can specify an ad URL for a third party ad server, rather than defining the creatives and uploading the media files.


VAST (“Digital Video Ad Serving Template”, see http://www.iab.net/vast) is the IAB (Interactive Advertising Bureau) specification for an universal XML schema for serving ads to digital video players, and describes expected video player behavior when executing VAST formatted ad responses.


  • VAST facilitates third party video provider to transfer data from ad servers to video players via XML.
  • The VAST XML contains the video assets, URLs and tracking pixels required for the ad. The publisher video player parses the XML file for these elements.


To determine what percentage of the ad is in view, you need to detect:

  • The ad's relation to the browser window dimensions
  • The ad's scrolling position
  • The ad's web page focus

A VAST XML that executes within the video player cannot detect viewability values.

  • If the VAST XML is combined with a VPAID communication, dynamic interactions between the ad and the publisher page can be enabled.
  • In result, the code executed captures real-time data that can be used for viewability reports.


  • VPAID (Video Player-Ad Interface Definition, see http://www.iab.net/vpaid) provides a method of communication between the ad and the video player.
  • While VAST XML alone supports only simple in-stream video ads, the IAB recommends the use of VPAID in addition to the VAST XML ad response. This VPAID communication between the ad and the video player enables:
  • A rich, interactive in-stream ad experience
  • Capturing additional ad playback and user-interaction details
  • Layering VPAID onto the VAST XML allows an "executable" ad to be displayed in any compliant video player.
    An "executable" ad is an ad that requires software logic to be executed during ad playback.


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