Referral Exclusion List in Google Analytics Explained

A common issue I see in analytics audits is confusion over what the Referral Exclusion List is supposed to be used for. I hope to clear up some of that confusion in this post.

What Is the Referral Exclusion List?

When Google released the Universal version of Google Analytics, one of the upgrades that came with it was the Referral Exclusion List. You can find it in your property settings by navigating to Admin > Property > Tracking Info > Referral Exclusion List. Then click the + Add Referral Exclusion button, drop the domain into the Domain field (e.g., annielytics.com), and click Create.

There are two primary issues that Referral Exclusion List seeks to resolve:

Self-Referrals

Self-referrals have been a significant issue in Google Analytics since its inception. We’ve all seen them. You go to your Referrals report (Acquisition > All Traffic > Referrals) and find your own site as one of your referrals. For some sites, their own site was in their top 10 referral list before the Referral Exclusion List. And I’ve even done analytics audits and found sites where they are their own top referral.

Lost Credit for Conversions Using Third-Party Tools

When you use a third-party tool that takes a visitor off your site to accomplish some task (be it PayPal, Eventbrite, Freshdesk, etc.) or to a partner site, if the visitor returns to your site to convert or land on a thank you page, the conversion would be credited to the third-party site.

For example, let’s say you are running an event, and you use Eventbrite for event signups. When the visitor returns to your site after signing up and lands on your thank you page, which you use to track a goal conversion, the credit for the conversion would go to Eventbrite. Scandalous, I know.

How Does It Help?

Without the assistance of the Referral Exclusion List, a referral triggers a new session. When you exclude a referral source, visitors who arrive to your site from the excluded domain do not trigger a new session. If you do not want traffic arriving from a specific site to show up as a referral or to trigger a new session when returning from the third-party to your site, you will need to include that domain in your Referral Exclusion List.

So let’s say a visitor comes to your site from Facebook and moves to your third-party site, abc.com. When s/he returns, without the Referral Exclusion List, a new session would be initiated, with the referral coming from abc.com. With abc.com listed in your Referral Exclusion list, the referral would come from facebook.com.

Limitations

The Referral Exclusion List preserves the sanctity of the session. BUT it’s duct tape; it’s a plan B, if you will. If you need to know what your visitors are actually doing on your third-party domain (especially if they’re actually converting on that domain, like with PayPal**), you need to set up something called cross-domain tracking. Then you will be able to track your visitors from your domain to the partner site as if they never left your site.

Merely adding a site to your Referral Exclusion List will not allow you to see what your visitors do on the partner site. All of their activity on that site(s) will be unknown to you. Think of that site as a black box. But if you do set up cross-domain tracking, you still need to make sure the third-party/partner domain is listed in the Referral Exclusion List.

**It’s beyond ridiculous that you still can’t add a tracking pixel to your PayPal pages in 2016! If you want to use PayPal, stick to PayPal Professional. Visitors stay on your site.

Why You May Still Have Conversions Attributed to Your Site

For a while you may still see conversions attributed to your own site or a site you excluded. That’s because returning visitors who were cookied before you set up your exclusions will have their conversions attributed to the referral because in the last-click conversion model, direct doesn’t get credit for the conversion if the visitor has visited via a different campaign. (Learn more in this post about Multi-Channel Funnels.) But eventually those cookies will die off, and these conversions will attribute to the original referral.

Common Mistakes

There are some mistakes I see somewhat frequently with the Referral Exclusion List:

• Removing your domain: When you upgrade to Universal, Google automatically adds your domain to the list. But it’s a common mistake to remove your domain from the list.
• Including subdomains: You only have to list domains. You would only list a subdomain(s) if you only wanted to exclude specific subdomains on a domain.
• Listing spam sites: The Referral Exclusion List does nothing to squash spam, so don’t list spam sites. All it will do is cause that traffic to show up as direct.
• Including the wrong sites: So partner sites are tricky. If you’re using another site you control for something like checkouts or conversions and you want to preserve the original referral for conversions, then it may make sense to include it in your Referral Exclusion List. But that doesn’t mean to throw every site you own onto that list. It will result in traffic from those sites showing up as direct. It would be much better to set up a custom channel that you call Partner and include your partner sites in it. You can learn how to do that in my Channels Guide. I once had a analytics audit client get a post published on Huffington Post. In their excitement, someone excluded huffingtonpost.com. I explained to them that because of that, all of that delicious traffic showed up as direct. Again, I recommended that they create a custom channel for their syndicated content rather than use the Referral Exclusion List.

How to Test

One way to validate that the Referral Exclusion List is working properly is to use Google’s Tag Assistant (learn more). When you traverse domains, it can tell you whether an additional session was created. Look for a flag that looks like this: