It is all about fill-rate. At a given point in time an ad-server may not have inventory to return a VAST response with an available creative included. Fill-rate for an ad campain can be anywhere between 5% to 95%. Fill-rate may vary based on country, audience, ad-type (in-stream vs. out-stream) or your contract with the ad service provider. On top you must account for potential network errors as the VAST process typically requires several HTTP requests to complete.
A solution to maximise fill-rate is to use ad waterfalling. This can either be a player-side or server-side process. For client-side waterfalling you can use the
adTagWaterfall setting to maximise fill-rate and thus revenue with Radiant
Media Player. Using this setting requires you to use at least 2 different ad service provider so that the player can waterfall from one to another.
Radiant Media Player supports two modes for ad waterfalling:
adTagWaterfallplayer setting: VAST tags for waterfalling are passed to the player as a configuration option. The player will sequentially run through all available VAST tags until it finds one that is suitable or has no more VAST tags to waterfall upon.
Specifies an array of backup VAST tags if the first
adTagUrl produces an error. The player will cycle through all available VAST tags (in order) in
adTagWaterfall until one is available or will resume content if no valid response is found (e.g. no inventory). Default:
When the player tries to load a new VAST tag with the
adTagWaterfall setting, a
adclientsidewaterfallrequested API event fires
Player code example:
The player will automatically follow any VAST redirect information (VAST Wrapper) until it finds a suitable VAST response or has no more redirect to follow. This may be configured with your ad service provider.
If you use Google Ads refer to this article for more information on video fallback.
When no valid VAST response after one or more Wrappers is available the player will fire an
aderror event. The
getAdVastErrorCode API method shall provide the error code 303 (Empty VAST response returned). See
VAST 3 video error
codes for more information.
The player will always look for VAST-embedded waterfall before using data in the
adTagWaterfall setting when both waterfalling options are available.