Data impact of cross-device visitor identification
Overview of how enabling cross-device visitor identification affects the data that you see in reports.
To understand how this feature affects data collection, it is useful to understand the visitor data fields in a visitor profile:
Visitor ID cookie
ID generated automatically on the first visit from a device or browser and stored in the s_vi cookie.
Visitor ID variable
Optional visitor ID that is set using the s.visitorID variable. This value is populated after a user authenticates and might match an ID that your company uses to track a user across multiple digital marketing channels.
Effective Visitor ID
The effective visitor ID is the actual ID for the user profile. This value is set to the visitor ID cookie, or to the visitor ID variable if one is provided.