VAST Demystified: Everything You Wanted and Need to Know

VAST Demystified: Everything You Wanted and Need to Know

You’ve heard of VAST. You know it has something to do with serving video ads that you either need to know how to format or be compatible with (depending on whether you’re an advertiser or publisher). The technicalities and purpose of it however – are lost on you.

No fear! We at Next Millennium can walk you through the basic questions and understanding of VAST in normal speak (as much as possible anyway – because some of it is, well, technical).

What is VAST?

VAST stands for Video Ad Serving Template. It’s a way to write script for video players and ad servers. The uniformity and standardization of the script allows for seamless usage across different ad players and servers.

The value of ‘seamless’ in this case means more revenue for publishers, and more reach for advertisers – as the ads can play anywhere that is VAST supported (which due to its effectiveness, is ubiquitous across the web).

Why was VAST needed?

As video ads on the Internet increased across the way back in the early aughts, a need for standardization rose, as not all ads could play on all ad players. Publishers often had to use two different players and there would be many errors that frustrated users, advertisers and publishers.

In 2008, the IAB (Interactive Advertising Bureau) developed VAST to standardize the way video ads are programmed once retrieved from servers. The simple logic being if all ads are formatted the same way, then an ad player will know what to expect when it comes across one and the actions will be familiar and consistent.

What can VAST do for my ads and revenue?

When ads are formatted with VAST tags, they can be viewed nearly anywhere globally. It’s a simple step to have incredible reach.  

For publishers, ensuring that they can play the most possible type of ads is common sense to optimize ad revenue.  

For advertisers, ensuring all your ads have VAST tags so players can easily play them is key to reaching marketing KPIs. 

Benefits of VAST 

Due to the uniformity of the template, it spawns several direct advantages

  • Clarity of role and expectation of every ad
  • Few playback errors
  • Greater adaptability and revenue or publishers and advertisers
  • Easier tracking and analytics

History of VAST

VAST was developed in 2008, and has gone through several iterations. Each version addresses different needs and updates functionality like skippable linear ads.

It’s currently up to version 4.0, however most publishers are still using the 2.0 version. This is fine because VAST is what they call “backwards compatible” – meaning any version of VAST is compatible with another. So even though a player may have updated to 4.0, it can still run 2.0.

Information VAST provides to Publishers and Advertisers.

By utilizing VAST, both publishers and advertisers will receive uniform reporting data on the performance of the ads: viewability, CTR and the like. 

Both can use the data to optimize their offerings. By having it in a consistent standard format, they can more easily compile and analyze it, without having to reference different data sets and make them compatible.

Information VAST provides the Video Player

What does VAST actually say in such a uniform way? It gives the player instructions on how to play the ad the server just retrieved. Things like placement: pre-roll, mid-roll and post-roll. Playing functions like play, pause and skip. It also includes information on where to send tracking information, like viewability and CTR.

What do VAST tags look like? 

It looks like a bunch of code, but if you want to make sure you’re looking at the right thing, this is what they usually look like:{{40631}}&h={{HEIGHT}}&w={{WIDTH}}&cb={{CACHEBUSTER}}&ip={{IP}}&ua={{USER_AGENT}}&dnt={{DNT}}&content_cat={{IAB_CATEGORY}}&device_make={{DEVICE_MAKE}}&device_model={{DEVICE_MODEL}}&device_os={{OPERATING_SYSTEM}}&device_osv={{OPERATING_SYSTEM_VERSION}}&app_bundle={{APP_BUNDLE}}&app_name={{APP_NAME}}&app_store_url={{APP_STORE_URL}}&ifa={{DEVICE_ID}}&gdpr={{GDPR}}&gdpr_consent={{CONSENT}}&us_privacy={{US_PRIVACY}}&coppa={{COPPA}}&content_id={{CONTENT_ID}}&content_episode={{CONTENT_EPISODE}}&content_title={{CONTENT_TITLE}}&content_series={{CONTENT_SERIES}}&content_season={{CONTENT_SEASON}}&content_genre={{CONTENT_GENRE}}&lmt={{LMT}}

Notice that there are words there that make sense, like ‘device’ and ‘height.  If you were to collapse the criteria, you’d see the parameters each tag has, like one duration may be 6 seconds, another 15. 

How many do I need?

More than you think. Every ad needs a VAST tag – and VAST tag is needed for every website you have. It’s not a “one ring to rule them all” situation, more like a custodian with a huge keyring with one for every room. 

What is XML, and do I need to know it for VAST?

XML is the coding language VAST uses to communicate between the ad servers and media content. XML is cool in that it’s a m

arkup language, which means it makes notation and comments on other coding languages. It’s also readable, meaning it’s not in zeros and ones incomprehensible to the average person.

Do you need to know XML to use VAST? 

Nope, unless you plan on creating your own tags. Which leads to the questions of:

Should you create your own tags? 

It’s unnecessary, as you can create one for free in Google Ad Manager or your ad provider may do it for you as well. Therefore, knowing how to technically write one is of little value unless you like obscure bragging rights.

Is VAST XML or URL – and what’s the difference ?

This is a techie question that most publishers, except for the curious geeky ones, need to know. 

Basically, there are two ways DSP accepts VAST tags. Some want it in XML format (most common) and others want it as a URL. 

Others don’t care. They just want the information. What publishers and advertisers need to know is the preference of the DSP they use most, and make sure their tags are in that format.

The next obvious question is how to get in a URL (we already covered XML) and the answer is the same, Google Ad Manager, or your ad provider will give you an option on which format to use. That’s all.

What do publishers need to know about it? 

We’ve basically covered it, but if you’re just skipping to this section to know brass tacks here, we go: 

Video ads are growing exponentially, the ability to play them on your site is vital to is review growth. VAST is a script template that enables video players to easily receive ads and play them according to the advertiser’s specification. Ensuring that the video player you use supports VAST will increase your revenue and your players stability.

What do advertisers need to know about it? 

If you’re just scrolling here to see what you need to know, this is it in a nutshell, read the rest for more details. 

Video ads are growing exponentially, advertising in this format is to your benefit. Once you’re creating a video ad, giving it the ability to be seen by the largest audience is to your best interest, VAST makes that happen. It’s a uniform template script that is compatible with most video players giving players the ability to play ads to each advertiser’s specification with errors being rare.  

To utilize it, VAST advertisers need to generate VAST tags for each ad they have which will give instructions to video players on the how’s and when’s of playing the ad, and then where to follow up with analytics. Advertisers can create tags in Google Ad Manager or their ad provider. Using VAST will increase the viewability and CTR of your ad campaigns.

What problems does it have: 

We said errors are rare, but they do happen (they’re usually your fault – just saying) so there’s that. 

The IAB has a list of all error codes VAST can return and what each one means. Depending on the error, the ad may be played or not. It may be a fatal error and needs to be completely formatted. 

To avoid errors, advertisers should verify their VAST tags with their DSP. A bonus would be to coordinate with your SSP and other ad partners and ensure consistency!

Another issue that sometimes arises is increased latency when interacting with players that don’t have as much functionality that VAST is asking of it. This is a publisher problem, and making sure your video player is as sophisticated as it could be is a priority particularly with Google Core Web Vitals being such a focus these days.

Esther Kurtz