One of our customers implemented Google Analytics on their website to get lots of information about visitors and leads.

 
 As many of you may know, one of the best practices for tracking is to add the GA (Google Analytics) tag using the GTM (Google Tag Manager) to reduce the number of scripts on the actual website structure.
 This customer uses Marketo as their marketing automation platform and needed the best possible sync to be created between the two platforms (GA & Marketo), in order to track visits for the long run, even if the user visited as an anonymous person. The client asked us to create a field in Marketo that will get and present the Client ID from GA.
 Upon activation, when a person visits a website that contains a GA tag, he often gets an internal Client ID in GA (the format, for example, is 123456.098765).
 

The first step we took to keep that data in Marketo was to create a Marketo field called ‘Marketo CID’ and add it as a hidden field in the forms. The value is updated through a cookie according to the Parameter Name.

 
 
 Marketo Autofill

 

We created a dedicated script and added it to the GTM. The script was designed to identify the Client ID from the GA and to transfer the value to the CID parameter.

 In the test that we ran,
 1. We entered the website and got cookied. As an immediate result, we got a Client GA ID.
 2. Then we filled out a "Contact Us" form containing a hidden field (Marketo CID).
 3. Eventually, we entered the Marketo database and checked the Marketo CID field.
 
Marketo CID
 Marketo CID
 
The field received the same value as that of GA.
 
 You may also be interested to read about Marketing Automation Best Practices.