Attribution and persistence
This method of identifying visitors across devices is no longer recommended. See Cross-device Analytics in the Components user guide.
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, Adobe 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. When the new profile is created, one visit ends and another visit starts.
The example below represents 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. Post columns are typically seen in data feeds. See Data feeds in the Export user guide.
- 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), a 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.
If a user is new to your site (has never visited before on this device) and authenticates within approximately 3 minutes of arriving, no values persist to the authenticated profile.
The example below represents 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, they are 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 are not copied to the stitched profile.
- Marketing channels overwrite other channels on a subsequent data connection containing a first authentication for that device.