Interstitials

What it is

A full-screen creative displayed during a natural content transition — between articles, before a video, between game levels. Frequency-capped at the network layer (usually 1/session), which keeps the format from immediately destroying the publisher’s UX.

I treat interstitial like a hot version of push: high immediate response, fast audience-fatigue curve, day-7 numbers that need their own attribution column.

What I measure on interstitial

• CTR: 3.8–6.1% across Tier-1 iGaming Q2 2024 (n=1.8M impressions). That’s roughly 12–18× display banner CTR for the same offers. The dashboards quote this number a lot.
• CR-given-click day 1: 0.9–1.4%. Solid.
• CR-given-click day 7: 0.42–0.71%. The decay between day 1 and day 7 is steeper than any other format I’ve measured. Roughly half of the day-1 conversions are gone by day 7.
• Audience-fatigue curve: I modelled interstitial fatigue on a Tier-1 iGaming campaign (n=24,800 unique users, Q3 2023). CR collapsed 38% between week 1 and week 3 even with 1/session capping. Frequency caps don’t fix fatigue — they slow it down.

When interstitial is the right format

• iGaming player attraction with a deposit-bonus hook that converts in-session
• App downloads with single-tap store install — the click-to-CR latency is short enough that day-7 decay matters less
• eCommerce flash sales with a 24–72h window
• Popunder scaling where the publisher inventory supports interstitial without cannibalising pop

When it’s the wrong format

• Anything needing a multi-week consideration window
• B2B, SaaS, financial products with KYC steps after the click
• Audiences already running push at 2/24h frequency — overlapping fatigue
• Campaigns under 200 conversions where you can’t power-analyse the day-7 vs day-1 gap

Specs

• Pricing models: CPM · CPA
• Devices: Mobile + Desktop
• Geo coverage: 240+ countries
• Anti-fraud: Multi-layer filtering + ML scoring on every impression. Treat the dashboard CTR as a sanity check, not as the conversion signal.

If the marketing copy says “interstitial CTR is the strongest in the format,” they aren’t lying. They are reporting the easy number. Push the same conversation to day-7 CR per dollar and the picture changes.