Referrer Targeting | With our latest update of the Atomx UI, we added “Referrer” to the Domain Targeting Menu. As always you can target primary domains (such as mopub.com or smaato.com). Now you are also able to exclude/include subdomains, such as ads.mopub.com or ads.smaato.com. The new option “Referrer” is the same as normal domain targeting, except it’s based on the Referrer domain instead of the Primary domain.