Website experiences that include a shopping cart, booking engine, or other alternative domain can require edits to the standard Google Analytics tracking code in order to track the GA cookie across domains. If this code is not properly installed, you will lose the integrity of your channel data in Google Analytics.

The first clue you might have a cross-domain tracking problem is if you notice inflated direct traffic and revenue or leads, alongside deflated data in your other default channels. This can indicate that as users hop from the main site to the shopping cart, for instance, the GA cookie is being dropped. When this happens, channel attribution information is lost, and users are then registering as direct visitors. This often also leads to the duplication of sessions, compromising your overall traffic data.

If both domains are not included in the referral exclusion list, this traffic will register as self-referrals, or referrals from your own domain(s). The referral exclusion list can be found in Google Analytics under Admin > Tracking Info > Referral Exclusion List.

If you think you may be having an issue, here are a few ways you can confirm that and begin working towards a solution.

  1. First, enter your website organically on one screen and open the real-time report on another. Click into locations and find the city you are in, aiming to filter down so you can watch yourself hop around the site in real time in Google Analytics. This may not always be possible for sites with large amounts of traffic.
  2. At this point, you should jump from the main site to the second domain (and maybe even back again) while watching the Real Time > Traffic Sources report. If your medium switches from organic to direct in this process, it’s your first clue you may have a cross-domain tracking issue, but you should take a couple of extra steps to confirm.
  3. To confirm the presence of an issue, download the Google Chrome extension WASP.inspector, go to your site in an incognito browser, open developer tools (F12 in Chrome), and navigate to the WASP tab.

4. You may need to reload your page, but you should be able to see the GA Cookie or GA ID that has been assigned to you. This is how Google Analytics tracks your behavior on the site. Take note of the string of numbers assigned to you.

5. Navigate from your site to the cart on an alternate domain, and check your GA ID now. Does the last string of the four pieces to the GA cookie ID match what you had previously on the main domain? If they don’t match, you have an issue and GA thinks you are a new user – proper cross-domain tracking allows for the flow of that ID across domains.

Identifier (_ga): GA1.2.1434478290.1478271665

Issues with cross-domain tracking can be unique to your site and situation, but Google has documentation that should help you reach a solution. In today’s world, data quality is integral to making sound business decisions – follow this method to detect and confirm one of the most common GA issues.