An interstitial is a full-screen ad that appears at a break in the experience, then closes to return the user to what they were doing. Because it takes over the whole screen, it captures far more attention than a unit that shares space with content, and advertisers pay accordingly. The catch is that it interrupts the session, so where and when it fires decides whether it feels acceptable or intrusive.

How it works

An interstitial loads in the background and is shown at a designed transition point, most often between levels, after a task, or when moving from one screen to the next. It can be a static image, a video, or a playable unit, and it usually carries a close button that appears after a few seconds. Because it owns the full screen, it earns a much higher eCPM than a banner ad, which users can ignore while they carry on.

Interstitial ad vs. other formats

The defining trait of an interstitial is that it is publisher-initiated and unavoidable in the moment. The app decides to show it, and the user has to dismiss it to continue. A rewarded video flips that relationship, since the user chooses to watch in exchange for a reward, so it feels like a fair trade rather than a toll. An offerwall is opt-in in the same way but goes deeper, letting users complete larger actions for larger rewards. Interstitials earn well per impression, but because they interrupt, they have to be rationed.

Why timing and frequency matter

An interstitial shown at the wrong moment, mid-level or mid-task, breaks concentration and drives users away. Shown at a genuine break, the same ad barely registers as friction. Frequency capping limits how often interstitials appear per session so revenue does not come at the cost of retention. The goal is to place them where a pause already exists in the experience, then hold the frequency low enough that users do not feel taxed for playing. Some publishers also add a short grace period at the start of a session, so a user's first moments are never interrupted by a full-screen ad.

Interstitials and the offerwall

Interstitials and offerwalls solve different problems. An interstitial extracts value from users passing through a break, whether or not they want an ad. An offerwall waits behind an entry point for users who actively want to earn currency, and it pays out only when they complete an offer. Running both means a publisher can capture attention at transitions with interstitials while giving motivated users a richer, opt-in way to earn through the offerwall. One is interruptive by design, the other is invited, and together they reach users who would never respond to a forced ad.

Common mistakes to avoid

• Firing interstitials mid-action instead of at a clean break, which frustrates users and hurts retention.

• Showing them too often. A high frequency lifts short-term revenue while pushing users to churn.

• Judging interstitials on eCPM alone and ignoring their effect on session length and return rate.