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Glossary of Mobile Advertising Terms


What is a VAST Tag?

VAST Tag (short for Video Ad Serving Template) is a specification used to serve video ads. It was created by the IAB (Interactive Advertising Bureau). Its main function is to make the communication between the video player and the video ad server easier, and it also helps with the embedding of the in-stream video ads. In other words, VAST ensures that the video ads will appear correctly on video players.

How is a VAST Tag utilized?

Advertisers can make a use out of VAST as it enables them to serve ads into multiple ad inventories within video ad players. This makes things easier for advertisers as they don’t have to make their own ad servers. Instead, they can just look out for a third party video ad servers that support VAST and they’re good to go.

VAST tags can come in two formats, XML and URL. Depending on your choice of Demand Side Platform, you’ll be using one or the other, although if both are supported, XML is a better choice. You can think of VAST as a list of criteria and instructions that are given to the video players. Things like the duration of ads, which ads to play, is the ad skippable and similar.