Glossary

Ad formats

Ad formats are the different ways ads can appear in a mobile app. Each format has its own user experience, placement, and level of engagement.

In mobile growth, they answer the question:

“How will this ad show up for the user, and how does it fit into my app flow?”

For example:

Banner ads sit at the top or bottom of the screen while the app is in use.
Interstitial ads cover the entire screen during a natural break, like after finishing a level.
Rewarded ads let users opt in to watch a video or interact with an ad in exchange for in-app rewards.
Native ads blend into the app’s design and layout.
Rewarded interstitial ads (beta) show a full-screen ad with a reward, but don’t require explicit opt-in.
App open ads display when the user opens or returns to the app.

In AdMob, you create an ad unit and choose which format it will serve. Each format works differently:

Banner: Small, persistent ad that refreshes automatically. Best for steady but low eCPM revenue.
Interstitial: Full-screen ad shown between activities. Must be pre-loaded before it’s displayed.
Rewarded: Video or interactive ad that users watch voluntarily in exchange for a reward.
Rewarded interstitial: Hybrid between rewarded and interstitial, grants a reward but appears automatically at transitions.
Native: Ad designed to match your app’s look and feel. Flexible but requires custom design work.
App open: Full-screen ad shown when the app is launched or brought to the foreground.

The general flow is:

Choosing the right ad format is key to balancing monetization and user experience:

Publishers can maximize revenue by testing which formats generate the highest eCPM.
Marketers can align ads with moments of user attention without harming retention.
Users are more likely to accept ads when the format feels fair (e.g., rewarded ads).

Well-placed formats increase both revenue and user satisfaction. Poor placement or intrusive formats can frustrate users and increase churn.