What is an interstitial ad?
An interstitial ad fills the screen between one thing and the next. It appears at a transition (between levels of a mobile game, between articles in a news app, after a video ends, before a page loads) and covers the whole interface until the user closes it, waits it out or taps through. Interstitials can be static images, rich media or video, often with a countdown before the close button appears. The name comes from interstice, a gap between two things.
They are most common in mobile apps, where they are a mainstay of how free games make money. On the web they are used more cautiously, because search engines penalize intrusive interstitials that block content as soon as someone arrives from search. Rewarded video, where a player chooses to watch an ad in exchange for an extra life or in-game currency, is a close cousin and usually a better-liked one, because the viewer opted in.
Why it matters
Why an interstitial ad matters
Interstitials own the screen. For a moment there is nothing else to look at, which gives them higher visibility and engagement than almost any other display format, and the price to match. For app publishers they are often the most valuable placement they sell. For advertisers they offer a rare full-screen canvas on mobile, large enough for a proper image or a short film.
That same dominance is the risk. An interstitial that appears at the wrong moment feels like an obstacle, and the irritation lands on both the publisher and the brand. Used sparingly and at genuine pauses, interstitials are tolerated; used greedily, they push people to uninstall.
In practice
How an interstitial ad works in practice
- 01
Publishers decide where the natural breaks in their experience are and set rules for frequency: no more than one every few minutes, never on first launch, never in the middle of a task. Advertisers buy the placements through app ad networks and programmatic exchanges, usually on a CPM basis, with targeting by audience, app category and device.
- 02
The creative is designed for a full vertical screen: a strong image or the first second of video doing the work immediately, the brand visible from the start, a clear action and an obvious way out. Performance is judged on viewability, click or install rates and, just as importantly, on what happens to the publisher's retention when the ads run.
Watch out
What people get wrong about interstitial ads
Treating the captive moment as permission to annoy. People who are forced to look at an ad are not the same as people paying attention to it, and an interstitial that hides its close button or appears mid-action earns more anger than recall. The other mistake, on the web, is using them on entry pages. Google treats intrusive interstitials as a poor page experience, and an overlay that blocks the content a searcher came for can cost more in rankings than it earns in ad revenue. A third is reusing creative made for other formats. A landscape spot letterboxed into a vertical screen wastes the one advantage the interstitial offers: the whole phone.
