Expandable Ad

Definition of Expandable Ad

A display ad shown on a website that increases in size after the initial page load.

Expandable Ad in Depth

Expandable ads are a “high impact” marketing strategy that helps to overcome banner blindness and get the advertiser’s messaging through to visitors of a website. There are a number of different types of expandable ads. Specifically, these ads are often differentiated by the action that prompts the expansion. Some ads will expand automatically when a page is loaded; others will expand only when the user takes a certain action (such as clicking or hovering for a set amount of time).

Below is an example of an expandable ad unit in action:

Example of an Expandable Rectagle Ad

Technical Specs

The IAB specifies a number of standard expanding ad units, though custom sizes are also popular. The before / after dimensions of the most common expandable ad units are:

  • 300×250 to 600×250
  • 180×150 to 600×150
  • 160×600 to 600×600
  • 300×600 to 600×600
  • 728×90 to 728×315

When proposing or discussing an expandable ad unit, it’s also important to note the direction of the expansion. For example, if a site features a 300×250 ad unit in its right rail, the expansion would most likely need to occur to the left (i.e., towards the center of the page). Similarly, a leaderboard near the top of a page would most likely expand down.

The amount of work required to run an expandable ad depends on the infrastructure of the site and the platform used to serve ads. The links below include instructions for implementing expandable ad units in DFP.

Expandable vs. Pushdown

Expandable ad units extend to cover over the content on a site. A similar implementation is the pushdown, which moves all content on a page lower in order to create additional space for an ad unit.

Example of a Pushdown Ad Unit


The user experience is generally similar, but not quite identical. Pushdowns will require more work from a technical perspective on the publisher’s side, whereas expandable ad units are relatively easy to implement.

To Expand or Not to Expand?

Expandable ad units are a type of rich media, meaning that s special creative file is required. As such, most advertisers don’t produce expandable ad units when preparing for a campaign; these ads are still somewhat rare.

In general, the use of expandable ads diminishes the user experience. In other words, some visitors to your site may view these ads as disruptive and more annoying than standard display ads. As such, if these ad units are included on a proposal there should be a meaningful premium (i.e., higher CPM) relative to standard ads. As a rule of thumb, we would recommend pricing expandable ad units at a premium of at least 50% – 100% to standard display ads.

It would also be advisable to limit the frequency of expandable ads. Most visitors to your site will likely tolerate an occasional expanding ad that disrupts their experience. But if they encounter this every time, they may get frustrated with the poor user experience and slow speed of your site.

Adding high impact ad units to your offerings may seem like a huge task. But it can actually be very easy.

As mentioned above, many ad platforms can accept expandable ad units as third party tags, meaning the the process for uploading these is substantially similar to standard Flash of GIF ads.

For more disruptive ads such as pushdowns (and many more), Undertone is an ad network that may be worth investigating. This network deals exclusively in non-traditional ad implementations, allowing publishers to leverage their tech platform to get these ads up and running.

The resources section below has a link to Undertone’s rich media gallery, which includes examples of a number of high impact ad implementations.

See Also

Related terms include: Rich Media, Super Leaderboard.