One slot, several formats: video first, then iframe or native
Recipe for a native-video, outstream or master-header slot that shows a video ad when video demand fills and an iframe or native ad otherwise — priority tiers for the order, weights for a backfill share, the template's "next body" message, what moves the numbers, and viewability for display slots.
A common publisher set-up is one slot that should carry the best-paying format available: a video ad (an outstream or “native video” player in the article, or a “master header” at the top of the page) when video buyers fill, and an iframe or native ad when they don’t. In Epom that is not a special zone type — it is ordinary ad selection on one placement: priority tiers decide the order of the formats, weights decide a backfill share, and the template decides how each format is drawn.
Who this is for
Network managers building such a slot, and publishers asking why its numbers moved.
Prerequisites
- One placement for the slot (Site or Non-standard for a display-style slot).
- The formats as banners: for example Template banners on a video-player template, iframe or HTML Code banners, native-styled Template banners. How each is drawn is the network’s template work — see Create and manage banner templates.
- Campaigns you can edit (Priority and Weight on the campaign’s Basic info).
Steps — set the priority: video first, then iframe, then native in one zone
- Put each format in its own campaign (or campaigns) and link all their banners to the placement.
- Give the campaigns priorities in the order you want the formats tried — for example video Premium, iframe Standard High, native Standard Medium. For every request the first tier that has an eligible banner wins and lower tiers are not consulted (how ad selection works).
- Let a lower format take the slot when the higher one has nothing: a video campaign that is out of budget, capped for this visitor or targeted elsewhere simply drops out of the request, and the next tier fills.
Give the backfill a fixed share instead
When the iframe ads should take, say, 10% of the slot even while video fills, put the iframe campaign in the same priority tier as the video campaign and split by Weight — 9 and 1 give roughly 90% and 10% of the requests both can serve. (In networks that run eCPM optimization the weight is not used to pick the campaign; see Optimization.)
When the video player gets no ad from its buyers
A video player inside a template asks its own VAST demand; if that comes back empty, the
template can ask the ad tag for the next ad instead of leaving a blank box — the Target related templates message described in
Create and manage banner templates.
With excType: "ALL" the loader re-requests and excludes the banners already tried, so the next
format in your order gets the slot.
Why did impressions jump (or drop) on this slot?
The slot shows what selection picks, so a change in its numbers usually has a cause in the set-up or the demand, not a fault:
- More (or less) demand in a higher tier — a new month’s video budgets, a new backup campaign, a cap or limit lifted. A higher tier takes every request it can serve.
- A banner enabled or linked somewhere it should not be. An extra iframe banner linked to the video slot in the same or a higher tier takes requests from video. Check the placement’s linked banners after every change.
- A template edit. Changing a template changes every banner on it — a lost progress offset or a broken player in a new template version shows up as a drop across all slots using it. See Create and manage banner templates.
- Requests themselves changed — compare Requests for the placement in a General report before and after; if requests fell, the cause is on the page, not in Epom.
Viewability for display and master-header slots
For a slot whose ad is display markup (an iframe, HTML or template banner), tick Enable viewability tracking (Beta) on the banner — shown on Site and Non-standard placements, and only on roles it is switched on for (no stock role; ask your network manager). Epom then adds a small script to that banner’s markup that watches the ad’s area on the page:
| Event | When it fires |
|---|---|
| Viewable | At least 50% of the ad’s area has been on screen for 1 continuous second — the first time |
| Repeated viewable | Each later time the ad comes back into view for 1 second |
| Undetermined | The browser could not run the measurement |
The events land in the same Viewability columns as video viewability (Split columns by → Viewability in the report builder) — see Video viewability and Open Measurement. There is no Not viewable event for display banners. Numbers start from the moment you tick the box — earlier impressions have no viewability data. For a video ad in the slot, viewability comes from the VAST tracking instead (same page).
Corner cases and gotchas
Corner case: the viewability script is not added to Always redirect answers — a redirect has no page area to measure.
Corner case: the measuring script is attached to the banner, not the placement: tick it on every banner of the slot whose viewability you want reported.
Corner case: a campaign on the House Ads priority has its weight set to 0 and its optimization switches turned off, so it cannot share a tier by weight — use it only as the last fallback, not for a fixed backfill share.
Per-role notes
- Publisher: without edit rights on the campaigns, ask the network manager to change priority or weight, and use the placement’s General report (Requests, impressions per banner) to see which format took the slot.
- Network manager: builds the whole set-up — campaigns, priorities, weights, links and templates.
- Custom-role users: the Priority and Weight fields, and Enable viewability tracking (Beta), are switched on per role; a read-only grant shows the value without letting you change it. Ask your network manager for any that are missing.
