What is an ad unit?
An ad unit is the configurable placement inside an app or website where a chosen ad format is shown to users, such as a banner, interstitial, or rewarded video. Each ad unit bundles a specific ad format, its placement settings, and a unique ID together, so a mediation platform can request, track, and report on that exact spot separately from every other spot in the app.
How do ad units work?
An ad unit is built from three key components:
- Ad format: The type of creative shown, such as a banner, interstitial, rewarded video, native ad, or offerwall.
- Placement settings: Rules such as eCPM targeting, frequency capping, and pacing that determine when and how often the ad unit is shown.
- A unique ad unit ID: An identifier generated when the ad unit is created. The mediation SDK uses this ID to request, track, and report on that specific ad placement.
When an app reaches the point where an ad is configured to appear, such as a level break, menu screen, or natural pause, it sends an ad request through the mediation layer. Ad networks then compete to fill that specific ad unit, and the winning creative is displayed according to the unit's format and placement settings.
In Unity's ad mediation dashboard, each ad unit is created and configured individually with its own ID, format, and placement settings. See Unity's ad-unit setup documentation.
Common ad unit formats
- Banner: A small, rectangular ad unit anchored to the top or bottom of the screen that can refresh automatically.
- Interstitial: A full-screen ad unit that appears at a natural break in the user experience, such as between levels.
- Rewarded video: An opt-in ad unit that gives users an in-app reward for completing a video view.
- Native: An ad unit designed to match the surrounding app or feed, so it blends naturally with the interface rather than appearing as a separate ad.
- Offerwall: A list of in-app rewards that users can choose from in exchange for completing an offer.
What are the benefits of using ad units?
- Granular reporting: Measure installs, revenue, and engagement for each ad unit instead of only at the network or app level.
- Format flexibility: Test or switch ad formats within individual placements without rebuilding the broader mediation setup.
- Precise control: Adjust eCPM targets, frequency capping, and pacing for each unit so different placements can be optimized independently.
What are the challenges of using ad units?
- Setup overhead: Each new ad unit requires its own configuration, including format, placement rules, and targeting, which can add work as the number of placements grows.
- Fragmented data: Creating too many narrowly defined units can split reporting across smaller data sets, making performance harder to evaluate and optimize.
- Consistency risk: Independently configured units can develop different capping and pacing rules, making it harder to maintain consistent settings across an app.
Frequently asked questions (FAQ)
What's the difference between an ad and an ad unit?
An ad is the actual creative a user sees, such as a video, image, or interactive experience. An ad unit is the placement and configuration that determines where and how that creative is served, including its format, settings, and unique ID.
Where should an ad unit be placed in an app?
Placement depends on the ad format and the user experience. Banner units are typically anchored to the top or bottom of the screen, while interstitial units are generally shown at natural breaks, such as between levels. Rewarded video units are typically tied to an optional action that users choose to complete in exchange for a reward.
Which ad unit format tends to earn the most?
There is no single highest-earning ad unit format for every app. Revenue can vary based on factors such as ad format, audience, placement, region, and advertiser demand. Rewarded video and interstitial units can generate higher eCPMs than banner units in some cases because they provide more prominent ad experiences.