Today, w let’s look at why and how to remove the MailChimp click tracking parameters (MC_CID and MC_EID) from your Google Analytics reports. Specifically, situations where landing page URLs in Google Analytics contain either the MC_CID and/or the MC_EID parameters.

What is MC_CID and MC_EID?

Both the MC_CID and MC_EID parameters are used by MailChimp to track clicks which come from email marketing campaigns. Specifically, when you integrate your Shopify, Woomcommerce, Magento or other ecommerce store with MailChimp,  these are used to track the campaign and user who access your website via emails to pass that information back to MailChimp. Creepy, yet really effective marketing indeed!

  • mc_cid: This is the campaign id which mailchimp passes for tracking the campaign-level conversion metrics.
  • mc_eid: This is the user id which mailchimp passes for tracking the user-level conversion metrics.

What’s the Problem with MC_CID and MC_EID?

Let’s say that you’re trying to analyze landing page performance and you see something like this:

The problem is this. Even though email sent all traffic to the same landing page, Google Analytics actually thinks that there are tons of different landing pages because each email click generates a different URL (because the mc_eid is different for each person). In other words, we can’t roll all traffic to this landing page (the homepage in this case) and thus, cannot analyze it. Google thinks that there are hundreds of pages but in reality, there’s only one page!

How to Fix/Remove MC_CID and MC_EID in Google Analytics

Fixing MailChimp tracking ids in Google Analytics is easy. Here are the steps.

  1. Access the Google Analytics view with the issue
  2. Edit the View Settings in Admin
  3. Add the mc_cid and mc_eid parameters in the “Exclude Query Parameter” box (comma separated).

NOTE: The above screenshot also includes fbclid as the same issue can be caused by facebook.

Now, this fix only applies to future data so unfortunately, past data is stuck!

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