Ad preloading reference

Video advertising has come a long way from having a single static pre-roll ad served to all of your users. Ads are now programmatic and are able to not only check to see if you have enough inventory to fill the ad request, but also potentially target certain ads to certain users. Even though this all happens very quickly, it still typically results in users looking at a buffering icon while waiting for a pre-roll ad to load. In fact, the average ad loading time across our publisher network is approximately 4.8 seconds.

JWP is now able to provide opt-in preloading for ads which, when enabled, preloads ads before their time to play. By preloading pre-, mid- and post-rolls for the current playlist item, as well as the pre-roll for the next playlist item, users will spend little to no time waiting for ads to load. This will enhance the user experience and minimize user abandonment.

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If you are a developer, playAd() is not supported with ad preloading. Since calling playAd() immediately plays an ad, there is no time to preload an ad.

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It’s important to note that turning on ad preloading will likely result in an increase of ad requests that don’t result in an impression or an error because the ad is requested before the user clicks play or the player becomes viewable. A conversation with your ad server and or ad providers is necessary to ensure no negative impact.

What will be preloaded?

For Ad Preloading, we are focusing on requesting and parsing the VAST documents that ads have their configuration in. They are typically smaller in size so requesting these does not have a major impact on overall bandwidth usage.

In most cases, the actual media asset for the ad (i.e. the creative) will not be preloaded. This is to not only prevent the extra network requests and bandwidth usage, but various platforms also prohibit the preloading of media assets - most notably on mobile.

Ad Preloading is only supported when using the VAST and Google IMA ad clients. The table below describes whether or not the VAST and/or media can be preloaded in various environments.

FEATURE	IMA	VAST
VAST Preloading	Mobile & Desktop	Mobile & Desktop
Media Preloading	Desktop Only	None

VPAIDS

Ad preloading is most beneficial for non-VPAID ads. Publishers who utilize VPAID ads may not see a major improvement in performance as we do not preload media files, including VPAID creatives. The one exception is when using the "googima" ad client, the IMA SDK may choose to preload some VPAIDs on desktop.

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Google’s IMA SDK does preload some media assets on desktop browsers so this will result in preloading of some ad creatives on desktop when using the 'googima' ad client.

Video Example

When does the player start preloading the ads?

ASPECT OF AD	IMA	VAST
Ad Schedule	N/A	When using Player Bidding, the ad schedule will be requested when the bid response is received. In other situations, the schedule will be requested when the playlist item is loaded.
Pre-roll	For click-to-play and autostart: ‘viewable’ situations, the pre-roll will be requested when the playlist item is loaded. If autostart is allowed by the browser, the pre-roll will not be preloaded. For other autostart situations, the pre-roll will be requested when .on(‘autostartNotAllowed’) event fires.	For click-to-play and autostart: ‘viewable’ situations, the pre-roll will be requested when the ad schedule is loaded. If autostart is allowed by the browser, the pre-roll will not be preloaded. For other autostart situations, the pre-roll will be requested when .on(‘autostartNotAllowed’) event fires.
Mid-roll	The first ad in a mid-roll ad break will be requested approximately 4 seconds before the ad break starts. For other ads in the same ad break, they will be requested when the previous ad starts playing.	Approximately 5 seconds before the ad break starts.
Post-roll	N/A - This is not possible due to a limitation in the IMA SDK.	Approximately 5 seconds before the playlist item completes.
Next Playlist Item’s Pre-roll	Approximately 4 seconds before the current playlist item completes. If there is a post-roll on the current playlist item, the pre-roll for the next item will not be preloaded.	Approximately 4 seconds before the current playlist item completes. If there is a post-roll on the current playlist item, the pre-roll for the next item will not be preloaded.