Visitor stitching guidelines

The following are important guidelines for visitor ID attributes and visitor stitching:

• Uniqueness
  A visitor ID attribute must have at least 3 unique characters and be at least 6 characters long.
  Learn more about visitor ID attribute requirements.
• Case sensitive
  Visitor ID attribute values are case sensitive so, UserName@example.com is different from username@example.com. If the attribute values contain these variations, use the lower-case enrichment to normalize them.
• Multiple IDs
  Multiple visitor ID attributes are evaluated as an OR condition in order of attribute ID from lowest to highest (oldest to newest).
• Robustness
  Only user identifiers that are guaranteed to match the visitor across devices should be used for visitor ID attributes.
• Stitched visitor profile
  When multiple visitor profiles are stitched, the original profiles remain and a new visitor profile is created to store the stitched profiles.
• Avoid test data
  Be careful not to capture default or test values in your user identifiers, such as, undefined, unknown, or not set.
• Shared IDs
  Before stitching is enabled, determine how to handle shared IDs, such as those used at libraries or universities, so that multiple visitors are not stitched inadvertently.
• Size limit
  The maximum size of a visitor profile after encryption and compression is 400 KB.
• Shared devices
  When two users share a device, both users have the same anonymous ID. If they visit the same websites, but use different user identifiers (such as an email address or a customer ID), this is referred to as visitor switching. Tealium Support or Professional Services can assist you with implementing a solution to handle visitor switching. For more information, see the following Tealium knowledge base articles:
  • Anonymous User Tracking under ITP with Visitor Switching in AudienceStream
  • Visitor Switching in iQ
  • Visitor Switching in Tealium Mobile SDKs