---
slug: messgrenzen
title: "Where does measurement end?"
category: grenzen
locale: en
updated: 2026-10-12
keywords: ["measurement limits","coverage","gaps","causality","completeness"]
questions: ["What are the limits of Metrunio’s measurement?","What cannot be measured?","Limits of attribution","How complete is the data?"]
url: https://bench.metrunio.com/en/help/messgrenzen
---

# Where does measurement end?

**What are the limits of Metrunio’s measurement?**

Post-view is only measurable where your own tags may be served and the browser returns the view identifier: not every served ad is viewable, and not every viewable one can be linked to the purchase. Without consent, gaps arise deliberately, and a gap stays a gap, not a zero. Attribution describes assignment, not causal advertising effect.

- Post-view is only measurable where your own impression or viewability tags can be served. Closed platforms do not allow that everywhere.
- A served impression is not automatically viewable; only viewable impressions create post-view credits.
- A viewable impression without a click only reaches the purchase through the view identifier. That is a cookie of the measurement address that Safari and Brave discard in third-party context and Firefox puts into a partition from which it never reaches the shop. The linkable share is measured and shown as post-view coverage; what the browser drops is not replaced.
- Where signals are missing, no touchpoints are invented. Conversions stay visibly “unattributed”.
- Attribution describes assignment, not causal advertising effect. To measure the effect you need an experiment. Metrunio has one, and it is kept separate from attribution.
- Without consent, data gaps arise deliberately; coverage is shown in the portal.
- No complete personal journey across every platform and device.
- Funnel steps count per customer identifier. Without identify() a step counts per browser, so the same person on two devices counts twice. A funnel is built only from steps your code sends, not from page views.
- When two identities merge, the earlier of two conversions of the same step is kept. A return that was already reported to an ad platform cannot be recalled.

> **Note:** The stated coverage is itself a metric: it says how much of reality a number actually reflects.

## Also asked

- What cannot be measured?
- Limits of attribution
- How complete is the data?

## Related

- https://bench.metrunio.com/en/help/post-view-messung
- https://bench.metrunio.com/en/help/post-view-verstehen
- https://bench.metrunio.com/en/help/meta-google-messen
- https://bench.metrunio.com/en/help/cross-device
- https://bench.metrunio.com/en/help/experimente
- https://bench.metrunio.com/en/help/funnel-schritte-messen