Video (VAST)

What it is

Pre-roll, mid-roll and post-roll video delivered via the IAB VAST 2.0, 3.0 and 4.0 specifications, plus a corner-slider variant for sites without inline video players. The format with the highest headline eCPM in display and the longest list of caveats attached to that eCPM.

The comparative framing

Video is the format where the gap between marketed economics and tested economics is widest in the category. The matchups that matter.

• Video vs interstitial. Both are dwell-time formats. Pre-roll lives inside the video player and trades on the user’s intent to watch; interstitial lives at content boundaries and trades on the user’s tolerance for a frequency-capped interruption. For brand campaigns with viewability requirements, pre-roll structurally wins. For performance campaigns where completion-rate-weighted CPM is the budget reality, interstitial closes the gap.
• Video vs native. Different products. Native carries narrative; video carries production value. Sports content and VOD sites are where video earns its premium without question. News sites running native often outperform the same sites adding pre-roll, when the creative budget per video does not scale to the format’s expectations.
• Video vs banner with rich media. Rich-media banner has eaten part of the brand-video budget over the past five years, and the trade is usually correct for advertisers who care more about reach-frequency than completion. The reverse is true for advertisers underwriting completion-weighted impressions in IAS or DoubleVerify reporting.

Where video is the wrong call

• Performance advertisers without per-GEO creative budget. Video that does not localise reads as imported, and imported video creative under-completes by 30 to 50 percent compared to native-language production in my Q2 2024 benchmarks.
• Sites without inline video players. The slider variant exists but trades headline eCPM for inventory access; on most performance verticals, the trade is not favourable.
• Verticals where the conversion lives below the fold of the same session. Video is a brand-shaped format; the conversion arrives later, not on the same impression.

Specs

• Pricing models: CPM, dominantly. CPCV (cost-per-completed-view) is available on the major DSPs for advertisers willing to underwrite completion specifically.
• Devices: Mobile and desktop. Mobile carries the majority of in-app video inventory; desktop carries the majority of premium publisher inventory.
• Geo coverage: 240+ countries claimed industry-wide. Real video depth concentrates in Tier-1 plus a handful of Tier-2 markets where premium video publishers operate at scale.
• Anti-fraud: Multi-layer filtering and ML scoring on every impression. Video is the format where viewability vendors (IAS, DoubleVerify, Moat, originally Magnite-side measurement) have the most mature toolchain; reconciliation between server-reported and verified-viewable impressions is closer than for any other format.

Methodology in the appendix.