Attribution and persistence
When visitor profiles are merged after being associated with the same visitor ID variable, attribution is not changed in the historical data set.
- When the variable s.visitorID is set and sent on a hit, the system checks for any other visitor profiles that have a matching visitor ID.
- If a profile exists, the visitor profile that is already in the system is used from that point forward and the previous visitor profile is no longer used.
- If no matching visitor ID is found, a new profile is created.
When an un-authenticated customer first arrives at your site, that customer is assigned a visitor profile by Adobe Analytics. As shown in Unique Visitor and Visits Counts, on authentication a new profile is created. When the new profile is created, one visit ends and another visit starts.
On the first data connection
The example below is a representation of how data is sent to Adobe Analytics when a customer authenticates for the first time, on the first device:
- eVar16 has an expiration of 1 day and evar17 expires on visit.
- The post_visitor_id column represents the profile maintained by Adobe Analytics.
- The post_evar16 and post_evar17 columns show shows the persistence of eVars.
- cust_visid represents a value set in s.visitorID.
- Each row is one 'hit', a single request sent to Adobe Analytics data collection servers.
On the first data connection containing a previously unrecognized s.visitorID value ( u999 above), the new profile is created. Persistent values from the previous profile are transferred to the new profile.
- eVars set to expire on the visit are not copied to the authenticated profile. Note the value car above is not persisted.
- eVars set to expire by other measures will be copied to the authenticated profile. Note the value apple is persisted.
- For the eVars that are persisted, no Instance metric is recorded. This means when using cross-device visitor identification, it is possible to see reports where the Unique Visits metric for an eVar value is larger than the Instance metric.
On subsequent data connections
The example below is a representation of how data is sent to Adobe Analytics when a customer authenticates on a new device, after having previously authenticated on a different device:
When the customer authenticates his or her id is matched to the previous 'authenticated' profile - 2947539300. The profile used at the start of this visit ( 5477766334477) is no longer used and no data persists from the file.
- Geo-Segmentation data is recorded based on the first hit of the visit and does not change for a single visit regardless of the device used. This means on a subsequent data connection on a new device, geo-Segmentation data is generally not included.
- Technology columns such as browser, operating system, and color depth are recorded on the first hit of a visit. Like Geo-Segmentation values, they will not be copied to the stitched profile.
- A Marketing Channel such as Direct or Internal which is commonly set up to not overwrite another channel will overwrite other channels on a subsequent data connection containing a first authentication for that device, such as the first authentication shown in Unique Visitor and Visits Counts.
In some other cases data is not persisted from the unauthenticated to the authenticated profile.
- If a user is new to your site (has never visited before on this device) AND that user authenticates within approximately 3 minutes of arriving, no values will persist to the authenticated profile.