Today we’re launching Cross-Domain Analytics to help you understand how users browse across all your owned domains. We built Cross-Domain Analytics as an alternative to existing systems like Liveramp and BlueKai which use third-party cookies to tie users across domains. These are not only inaccurate by nature, but also facilitate sharing of user data across companies. We've built a system which both preserves privacy, but helps brands understand user journeys across domains they own.

Cross-Domain Analytics, now available on the Business plan, appends a new Cross-Domain ID to users who browse multiple sites you own. This lets you answer key business questions that require an understanding of users across your domains. For example:

  • Marketing Attribution. Understand how user behavior on your editorial or promotional micro-sites leads to conversions. Then optimize your micro-sites to drive conversion to your core product.

  • Content Coordination. Measure how readers browse content across your domains. Decide whether to replicate content across brands or specialize on separate topics.

  • Post-Acquisition Strategy. Measure how users on a newly acquired domain overlap with your existing properties. Use that data to develop an effective segmentation and brand strategy.

At Segment, we already make it easy to analyze customer behavior across an individual domain and its subdomains in tools like Mixpanel or Amplitude. These tools use a combination of Anonymous IDs and User IDs to do funnel analysis, attribution, A/B testing, and more. However, these identifiers are unique to individual domains: an Anonymous ID on, an online cosmetics brand, will be different than the same person’s Anonymous ID on, Glossier’s cosmetics blog. Segment’s Cross-Domain Analytics feature simply appends a new identifier, the Cross-Domain ID, to every API call. The identifier is consistent across a single company’s domains and can be used to join together event data in warehouses like Redshift and BigQuery.

When you turn on Cross-Domain Analytics, we’ll pipe the enriched events and traits into your data warehouse. From there, you can write queries that answer your business questions. See our technical docs for more details.

Let’s take a closer look at one use case for Cross-Domain Analytics. Glossier is a popular online cosmetics brand. The Glossier team regularly uses funnel analysis to improve conversions on the e-commerce site,

However, the company started out as a blog, Into The Gloss, which has its own domain, It’s a vital part of how Glossier interacts with its customers, yet out of the box analytics tools can’t connect user behavior between the two sites.

Segment’s Cross-Domain Analytics allows the Glossier team to do just that. They join page viewed data from Into The Gloss and conversion event data from Glossier on the Cross-Domain ID.

Select count(*)
From intothegloss.pages
Inner Join glossier.item_purchased
On intothegloss.pages.context_traits_crossDomainId = 
Where = 'Meet Invisible Shield' AND
    glossier.item_purchased.product_category = 'Invisible Shield'

These queries give companies like Glossier the complete customer journey.

Learn more about how Glossier uses Segment to unify their customer data across every domain and touchpoint.

Like the rest of our customer data infrastructure, Cross-Domain Analytics lets customers get more value out of their own data while keeping that data private. Unlike third-party data aggregators, Cross-Domain Analytics cannot be used to track users across multiple independent companies.

If you’re new to Segment, Cross-Domain Analytics is a quick path to new and actionable insights. Schedule a demo to learn how you can collect, unify, and act on your data with Segment.

If you’re a current Business plan customer and want to add Cross-Domain Analytics to your Segment toolkit, let us know!