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Adobe Summit 2019 | S903 - Mastering Visitor Identification


Level 10


Session Details

Hear directly from Adobe Analytics experts who engage on a day-to-day basis in solving the most critical and complex Adobe Analytics queries. This technical session will help you understand Adobe Experience Cloud visitor identification, common pitfalls, and related industry complexities.


  • How Adobe Analytics identifies visitors
  • Intricacies of the Experience Cloud ID service
  • Commonly misunderstood concepts: visitor migration, grace period, and CNAME
  • The impact of intelligent tracking protection on visitor identification


Erin Davis, Product Manager, AEP Identity Service, Adobe

Ankit  Sharma, Analytics Technical Support Consultant, Adobe

Aaron Hadley, Lead Technical Support Consultant, Adobe

Session Length

1h 30m

Catalog Link

S903 - Mastering Visitor Identification




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Please use this thread to ask the question related to this Session.

5 Replies



How are CNAME's used with the ECID Service?

Following the session, there was a fair amount of confusion about the role of CNAME's in visitor identification.  We spoke about CNAME's in two different contexts, which I'll attempt to clarify here.

1.  Cross-Domain Tracking:

For browsers that block 3rd-party cookies, including Pre-ITP 2.1 Safari, CNAME's could facilitate using the same AMCV cookie values between domains, provided that visitors first navigated to the CNAME domain, then to other domains.  This option, no longer works in Safari with ITP 2.1.

The primary option for cross-domain tracking would require passing the visitor ID via the query string when navigating from one domain to another using the appendVisitorIDsTo method of the ID service object.


2. ITP 2.1 7-day Cap

ITP 2.1 will remove client-side (document.cookie) first-party cookies after 7 days.  The ECID service AMCV cookie is among those cookies impacted by these changes.  Using a CNAME, in combination with the pending update to the ID service library, provides an effective way in mitigating the impact of this 7-day cap.

We recommend that customers consider moving to a CNAME implementation moving forward to address concerns related to the 7-day cap.  More information about CNAME configuration can be found here:  https://marketing.adobe.com/resources/help/en_US/whitepapers/first_party_cookies/adobe_managed_cert_...

In summary, CNAME's were historically valuable in some cross-domain scenarios but will no longer address this use case for Safari users.  However, CNAME's are recommended for the separate purpose of addressing ITP 2.1 first-party cookie caps (7-day).  Additional details will become available as the updated ID service library is made available.


Level 2

AnkitaSharmaerindavis​ Per our conversation after the session, setting a CNAME does not solve the cross domain issue with ITP 2.1. You mentioned that the only way to be able to do cross domain tracking properly with ITP2.1 at this time is to embed a code to the url that is going to the other domain. Can you please provide a link to the resource on where I can find out the details on implementing that?




See the appendVisitorIDsTo method of the visitor object.  This will help with passing the visitor ID via the query string when navigating from one domain to another.



Level 4

Hi jantzen,


I've tried playing the video recording it's not working. Can you please help me how to accomplish the recording session.