Google Ad Manager interstitial ads

What are interstitial ads? How to setup them on GAM? Can we setup header bidding to compete for interstitial ads? All the answers in this post.
Interstitial ads

What are interstitial ads

Interstitial ads are full-screen ads that appear in between content, such as when a user transitions between different pages or views within an app or website. They are commonly used by advertisers to grab users’ attention and promote their products or services.

Interstitial ads can come in different formats, including static images, videos, or interactive content. They are typically displayed for a few seconds before allowing the user to continue to their desired destination. Some interstitial ads also offer a “skip” or “close” button, allowing users to bypass the ad and continue with their intended action.

Are GAM interstitial ads a good solution?

Unlike other types of ads that can be ignored or easily dismissed, interstitial ads are designed to interrupt the user’s experience and demand their attention. This can be a double-edged sword for advertisers, as it can result in high engagement rates but also lead to negative user experiences and ad fatigue.


  • High CPM
  • High fill rate
  • High viewability
  • High CTR


  • Disruption of user experience
  • Higher bounce rate

Despite their potential drawbacks, interstitial ads remain a popular advertising format for their ability to deliver high click-through rates and engagement. They are particularly effective for mobile apps, where users are often more engaged and spend longer periods of time within the app.

However, it’s important for advertisers to use interstitial ads responsibly and in moderation to avoid overwhelming users and causing negative experiences. As with any form of advertising, a balance must be struck between promoting products and services and respecting users’ desires for a seamless and enjoyable experience.

How to create an interstitial ads on GAM

In this post we will help you to integrate interstitial ads in Google Ad Manager, previously known as Doubleclick For Publishers, DFP. This guide is meant for expert GAM users which already know how to create ad units and traffic them using orders and line items.

The following procedure works for both:

  • MCM MA (multiple account management managed account, sponsored AdX active in the child GAM account); replace 888888888888 with your GAM network code i.e. 1234567.
  • MCM MI (multiple account management managed inventory, AdX tags generated from the parent GAM account); replace 888888888888 with your parent GAM network code, your child GAM network code i.e. 8765432,1234567.


  1. Create an ad unit in GAM:
    – Name and code: UNIT_Interstitial
    – Sizes: 300×250, 320×480, 336×280, 480×320, 768×1024, 1024×768, Out-of-page
  2. Target the ad unit with the AdX line item. Preferably use the “all creative sizes” option.
  3. Insert this script in your page (head section), replacing your GAM network code:
    var interstitialSlot; googletag.cmd.push(function(){interstitialSlot=googletag.defineOutOfPageSlot('/888888888888/UNIT_Interstitial',googletag.enums.OutOfPageFormat.INTERSTITIAL);if(interstitialSlot){interstitialSlot.addService(googletag.pubads());googletag.pubads().addEventListener('slotOnload',function(event){});}googletag.enableServices();});googletag.cmd.push(function(){googletag.display(interstitialSlot);})
  4. Only if you didn’t insert the GPT libraries before, add this script above the previous one:
    <script async src=""></script>
    <script>window.googletag = window.googletag || {cmd: []};</script>

Is there a better way to create interstitial ads?

If you are an advanced publisher, you are probably boosting your website revenue with header bidding too. If this is the case, you should know that in most cases, prebid cannot participate to auctions for GAM interstitial banners. While Google provides a very easy integration for interstitial out of page ads, these ads will be trafficked only by Ad Exchange / AdSense line items or price priority line items.

If you want header bidding to bid for interstitial ads, you will have to code those ads by yourself using both javascript and CSS. Basically you need to define them like normal ad unit and hide them. At the right time you have to unhide them and call the refresh. You should store a cookie as well to limit the popup at one every 10 minutes for example. If you rely on support, we will support you creating interstitial ads eligible for both AdX and prebid demand.

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