How do I create a smart list that includes the Referrer URL data from the activity log?

Hi Joe,

I hope you don' mind If I update my answer - I did not initially get the part about form fill-out...

I have 3 options that come to mind. #3 is my preferred method...

1) You do have the option to grab the referrer by using a javascript that will put it in a hidden field in your Marketo form. Here is an article about it:  Re: Referrer Parameter

2) There is also a method to capture URL parameters from cookie value. Documented method does not actually grab the entire referrer, but rather some URL parameters, but I don't see a reason why it would not work for the entire referrer with a few tweaks to the script. (If you chose that option let me know we have an updated version of this script that  I can share.

Get URL Parameters via JavaScript on a Marketo Landing Page

3) My preferred option is to capture it at the visit no code required. I have a similar campaign currently running. You can do this using a smart campaign that triggers on visits to any web page and then stamp the referrer using the {{trigger.Referrer}} token in a dedicated custom field. I also filter out internal traffic using domain is not perkuto.com (our own domain)

Here is what it looks like.

First, Capture the Referrer on Page Visit

Then, you can , upon form fillout, pull the value that you just stored in the last referrer field as the last referrer for this specific form fill-out.

Other related resources: Set a Hidden Form Field Value - Marketo Docs - Product Docs