An essential aspect of ad serving is impression measurement. It is important to understand how and when Adhese counts an impression. There are two scenarios:
- An ad is requested and visualised.
- An ad is requested and could be visualised, depending on some rules like: minimal screen size, device rotation, in viewport, ... The impression is counted at a later moment (i.e. deferred impression).
The second scenario results in two types of requests:
- An ad request, and
- A track request.
An ad request is a request that returns an ad, the first scenario. A track request is executed after the initial ad request and acts as an impression request, the second scenario.
When track requests are used for impression measurement, the inventory will also be based on these numbers. In this way, the actual inventory is reported and used in forecasting.
The above explanation about impression measurement is applicable to any tag implementation method.
The Campaign actions report per position reports both the number of requests and tracks, along with other events.
A mismatch between the reports of a publisher and an advertiser is likely to occur – resulting in third-party discrepancies. Adhese (or the publisher's ad server) counts an impression when the request to serve an ad is made (ad request), while the advertiser may count an impression later on in the process of ad serving: when the ad is actually delivered to the user (ad delivery). For more information about third-party discrepancies, refer to Troubleshooting.