Campaigns and measurement
What do the macros in the tracking code mean?
Your ad server replaces [IMPRESSION_ID] with the identifier of the individual delivery and [CACHEBUSTER] with a random value. If [IMPRESSION_ID] is left unreplaced, the collector detects it and gives the pixel its own impression ID per delivery. The impression then counts, but the viewability tag reports nothing: without a shared identifier, viewability cannot be matched to a delivery.
What is [IMPRESSION_ID] and what happens if the macro is not replaced?
| Macro | Replaced by | Purpose |
|---|---|---|
| [IMPRESSION_ID] | identifier of the individual delivery | joins pixel, viewability and click |
| [CACHEBUSTER] | a random value per call | stops a proxy from swallowing the delivery |
| [CONSENT] | 1 when the publisher’s consent has been given, otherwise 0; set by the consent tool or the ad server | without 1 nothing is stored and no view identifier is set; a placeholder left in place counts as no consent |
| [SITE_DOMAIN] | domain of the website the ad runs on | shows in the report where the ad ran; if the placeholder stays, Metrunio reads the website from the referrer |
Macro syntax differs per ad server: some use %%CACHEBUSTER%%, others ${CACHEBUSTER}. Replace our placeholders with your system’s syntax before you traffic the creative.
If your ad server only ever delivers the creative with consent, choose “My ad server delivers this creative only with consent” in the tracking generator. The code then contains a fixed 1 instead of [CONSENT]. This is your statement; Metrunio does not check it, and it is recorded on every element generated this way. It does not replace proof of your visitors’ consent. Choose it only for a delivery chain you have checked and documented: which ad server, which publisher, which consent text, who is responsible. Beforehand, confirm with a negative test that without matching consent neither the measurement tag nor a positive signal is delivered. Metrunio does not check every single ad contact; you still need to resolve any sign of a misconfiguration.
Caution
If pixel and viewability tag receive different impression IDs, viewable impressions appear without a matching delivery. That surfaces as a finding under “Data status”.
Last reviewed on 15 Oct 2026
Also asked
- Macro is not replaced
- What is a cache buster?
- Impression ID in the ad server
- What does [CONSENT] mean?
- What does [SITE_DOMAIN] mean?
- Why does my copied code measure nothing?
Related articles
- How do I install the impression pixel?
How do I measure that a creative was served?
The impression pixel is a 1×1 image you place in the creative or the ad tag. It counts delivery, not viewability; that is what the separate viewability tag is for. It measures from the Pro plan upwards; on the free Start plan Metrunio accepts no impressions.
- How do I measure a creative’s viewability?
What is the viewability tag and when does an impression count as viewable?
The viewability tag is a separate script in the creative. It reports an impression as viewable once at least 50 per cent of its area has been in view for one second. Metrunio measures viewability from the Pro plan upwards, not on the free Start plan.
- How post-view is measured and where it is not
How does a viewable impression without a click get to a purchase in my shop?
Through a cookie on the measurement address: pixel and viewability tag set it with consent, the SDK in your shop returns it, and the link is made on the server. That works in Chrome and Edge, not in Safari, Firefox or Brave. How large the linkable share is for you is shown as post-view coverage in the portal.
- Why do I see no post-view touchpoints?
Viewable impressions do not appear in journeys. Why is that?
Post-view needs its own viewable impression signal. Without the viewability tag, or with a mismatched impression ID, no post-view contact is created.
- Which website did my ad run on?
Can Metrunio show on which publisher website an ad was seen or clicked?
Metrunio shows it for ads that carry your own tracking code. If your ad server fills the domain into the [SITE_DOMAIN] macro, it is stored with every impression, view and click. Without the macro, Metrunio reads the website from the referrer, as far as the browser sends one, and says that this is where the value came from.