A better understanding of the tracking system and why can we see impressions on unknown domains.
Our tracking is per default grouped under a domain as our products are mainly used by web applications. So when one of our ads are being served we get the url (for instance https://bt.dk) of the site serving our ad and make sure that all events are tracked under that domain.
When our tags are served in a native app we also get the domain but in this case we have found, we, in most cases get doubleclick.net. From that domain we are not able to determine where our ad was served as doubleclick.net is just a general domain Google uses when they are displaying ads in native apps.
Therefore we have included a macro in our third party tags for standard display that in those cases can be used to identify which app that actually served our tag.
In the picture below we have marked this macro for DV360 with blue. Macros in general are text that will be replaced by the ad server or DSP when an ad is being served.
Therefore, when one of our third party tags are being served this macro will automatically be replaced and when the third party tag are being displayed in an app they will in most cases be replaced by a domain like this app.name.goes.here.adsenseformobileapps.com where the "app.name.goes.here" will be the name of the app.
An example of this could be app.android.media24.netwerk24.com. This is not a real domain but something we can use to identify an app.
However there is cases where this macro will not be replaced by the DSP or ad server to something we can use to identify the app. And in those cases we have to fallback to doubleclick.net in lack of anything more precise.
Therefore, in those cases it's an issue between the DSP/Ad Server and the app and as we are not in control of these we unfortunately can't make our tracking more precise.