This article describes the visitor ID attribute and how to use it.

In this article:

How it Works

Before you begin, familiarize yourself with the following:

Identifying your visitors is a critical step in making full use of Tealium AudienceStream CDP. When certain qualifying visitor events occur, such as a user registering or completing a purchase, there is an opportunity to uniquely identify that visitor using an event attribute such as email_address_hash or customer_id. When one of these identifying attributes is provided in the data layer across multiple sessions, AudienceStream can combine the visitor attributes from those sessions into one master visitor profile using a process called visitor stitching. Visitor stitching uses a visitor ID attribute to identify users across sessions and devices.

A visitor ID attribute is configured in AudienceStream to uniquely identify visitors. When you create a visitor ID attribute, you add an enrichment to set the value to a user identifier, which is an event attribute, such as email_address_hash or customer_idFor visitor stitching to work properly, you must choose a unique user identifier, create a rule to determine when to identify a visitor, and verify that the chosen attribute is unique for each visitor.

Visitor stitching is disabled by default. Contact your account manager to enable it.

The visitor ID attribute is available in the following scope: Visitor.

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System Requirements

A visitor ID attribute must meet the following system requirements:

  • Length – Values must be between 6 and 255 characters in length.
  • Non-repeating – Values must contain at least 3 different characters. A 10-character identifier with only 2 different characters ( "a1a1a1a1a1" ) is invalid.
  • Enrichment – Attributes with a data type of Number cannot be used to enrich a visitor ID attribute. 

UTF-8 character sets are supported.

The system automatically validates these requirements. You do not need these rule conditions in your visitor ID attribute configuration.

Best Practices

A visitor ID attribute should follow these best practices:

  • Uniqueness - Each visitor ID attribute value should be unique for each visitor.
    • Strong identifiers - Only use values that could be associated with a single visitor and are not likely to change, such as a hashed email address or customer ID.
    • Weak identifiers - Avoid values that cannot be guaranteed to be unique for each visitor or that have a high likelihood of changing over time, such as first and last name, username, or phone number.
  • Case Sensitive - Values are case sensitive, so convert them to lower-case. For example, a single email address can be written with case variations such as and, which would be treated as two different IDs in AudienceStream.
  • Verifying the Value - If you are using an email address, you may want to verify that the address contains the @ symbol.  You may also want to check the string for other values such as, undefinedunknown, or not set or any text that would not be a valid value for a visitor ID attribute.

See Creating a Visitor ID Attribute for a guide to creating the most accurate visitor ID attribute possible.

Setting a Value for a Visitor ID Attribute

Set the value for a visitor ID attribute during a qualifying event, which is an event that occurs when a customer provides a reliable, unique means of identification, such as registering an account or completing a purchase.

A visitor ID attribute should not be a marketing activation ID (such as a gid). These third-party identifiers can be stored as visitor attribute for use in connectors, but are not recommended as visitor IDs.

Visitor ID Attribute Enrichment

This enrichment stores a user identifier for a visitor in a visitor ID attribute. For example, when a user registers or signs up, your system might generate an internal ID that is added to the data layer as customer_id. Use this enrichment to set a visitor ID attribute to customer_id when the user_register event occurs.

After a visitor ID attribute is set, it cannot be updated.

Attribute Name: customer_id

Starting Value ""
Enriched With customer_id: "123456890"
WHEN: User Register event occurs (rule)
Resulting Value "1234567890"

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