Interstitial Ads: Buy Full-Screen Ad Traffic

What you are buying

An interstitial takes the whole screen between two things the visitor chose to do. They tapped something, and before it arrives, your creative is what they get.

That buys attention no other format here can, and it buys it on a timer. The hand is already moving towards the close button, so a single claim and a single action have to be legible in the first second. A full screen is not an invitation to fill it.

It also means the visitor never asked for you and was interrupted mid-task. Everything else on this page follows from that: the cap, the creative discipline, and the preference for offers that work on impulse.

What interstitial traffic costs

Interstitial is billed per thousand impressions, and what the bid should be depends on the country and on how much demand is competing for the same screens. Live volumes and bids sit on the Available traffic page.

Expect a higher CPM than banner, and a higher share of people who actually register that an ad appeared. Against popunder, compare what a conversion ends up costing rather than what an impression costs. One format buys a whole screen mid-task and the other buys a page view found later, so the two impression prices are not measuring the same thing.

What it costs to start

Fifty dollars opens the account, and on interstitial it buys the fewest impressions of any format here, because the CPM is the highest. That is the trade for a whole screen instead of a corner of one.

The cap makes the arithmetic stricter. At one impression per person per day a first test cannot buy depth, only breadth, so choose a market where the CPM still leaves you enough distinct people to learn from. Running the same test in an expensive Tier 1 country on a starter deposit returns a number with nothing behind it.

How to launch an interstitial campaign

Create a campaign, choose interstitial, and build the creative for a full mobile screen rather than stretching a banner into one. Hold the opening run to one market and one class of device, and take the starting CPM from the Available traffic page.

The frequency cap goes in before launch, not after the first report. One impression per person per day is a sane default. No format punishes an uncapped campaign harder, and the damage lands on the brand as well as on the budget.

Frequency and the annoyance boundary

The same visitor seeing an interstitial repeatedly in one session does not convert better; they learn to dismiss it faster. Beyond a low frequency the format only spends budget.

Check the ratio of impressions to unique users after the first day. A number far above your cap means the campaign is concentrating on a narrow audience pool, which is a targeting problem rather than a format problem.

If your offer is tied to a date (a match, a deadline, a sale), concentrate the frequency around that date instead of spreading it across a month.

What to measure

Only one number decides an interstitial campaign: what you paid for each conversion, broken out by market and by source. Click-through here is flattered by accidental taps, particularly on phones, so a high rate sitting next to a poor conversion rate usually means the creative is catching thumbs rather than interest.

Split by device and connection type. This format varies by device class more than most, because the creative fills the screen and the screen decides how it reads.