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This article describes the visitor ID attribute and how to use it in the Universal Data Hub (UDH).

In this article:

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How it Works

Before you begin, familiarize yourself with the following:

Identifying your visitors is a critical step in leveraging the power of AudienceStream.  When certain qualifying visitor events occur, such as a user registering or completing a purchase, there is an opportunity to identify that visitor using an event attribute such as customer_email 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.

However, for visitor stitching to work properly you must carefully choose a visitor ID attribute and create a rule to determine when to identify a visitor. The value is a unique identifier such as an email address or customer ID.  

Visitor stitching is disabled by default. Contact your account manager to enable it.
Learn more about visitor stitching.

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

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System Requirements

A visitor ID 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 e.g. a 10-character identifier with only 2 different characters ( "a1a1a1a1a1" ) is invalid.

UTF-8 character sets are supported.

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

Best Practices

A visitor ID should follow these best practices:

  • Uniqueness – Each visitor ID 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 an 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 FirstLast@example.com and firstlast@example.com, which would be treated as two different ID's in AudienceStream.

Vendor Identifiers

Third-party vendors that track visitor activity also maintain a unique identifier for each user. These values can also be used as the visitor ID attribute in AudienceStream. To ensure uniqueness across all third-party vendors it's a best practice to create a separate visitor ID attribute for each vendor you work with. For example, if your visitors have accounts with Facebook and Twitter, create a visitor ID attribute for each vendor, such as "Facebook ID" and "Twitter ID".

Review the guide on visitor stitching to ensure you create the most accurate visitor ID attribute possible.

Visitor ID Enrichments

Set Visitor ID

This enrichment stores a unique identifier for a visitor. 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 to customer_id when the user_register event occurs.

Once a visitor ID 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"