Referrer URL and Lead Source - How To?

Sarah Mayer​ Referrer URL isn't widely used any more because it's entirely reliant on the website the lead is coming from to pass that data along during navigation, and most websites just don't bother any more. If the original website they're coming from doesn't pass along the Referrer URL data, there's nothing to pick up in that hidden form field, so you could get very inconsistent results.

A more consistent method would be to use URL parameters. That allows you to get full control over tracking your leads and how they get to your page. Check out the doc here: Tracking Lead Sources

To forward first-touch information through form fillout, you save the information to cookies and set up hidden form fields so you can later pull from cookie values (all Marketo hidden fields can be set to AutoFill from cookies). This applies both to the remote referrer, which is only readable on the initial touch, and to any explicitly source-tagged URL parameters (utm_* or other values) which are also only available on the initial touch.

As Mike points out, it is better to not rely on getting full referrer information, instead making sure to source-tag all your links. 

[I wouldn't phrase it the way Mike does that modern websites don't "bother" sending the referrer. It's more that they closely manage what parts of the referrer are forwarded to you to protect privacy and/or intellectual property.  So they may strip out the parameters of the referring page (?this&search&is&private) but still send you the bare hostname (google.com). As long as your first touch landing page is running you will still see the a ton of referrer info, and if it's the best you've got, it's worth using for attribution.  It will never be as complete as source tags, but you don't always have the chance to add tags, for example if someone organically shouts you out on their blog.]

Sarah Mayer

We have implemented something similar for some of our customers. Here's what we have created to track Lead Source Most Recent, in cases where we do not pass any value in the URL parameters.

- A JS code which captures the referral URL when a user visits the website. If the user came from Google Search Engine, we would store the URL in a custom cookie with the JS code.

- If the user fills a form in the same session or comes back later, we would read the URL from the custom cookie and pass it to Marketo when the form is submitted.

- Basis the value, we have created a smart campaign that would match the referral URL with our list of attributes and assign a lead source. As an example, if the referral URL contains 'gclid=', we know the lead came from a paid Google Ad. Similarly, we have around 1500 values in our attribution list.

- Once we have updated the LSM value in Marketo, we would change the Referral URL = NULL. Also, we have a time set for expiring the cookie to ensure that we do not get the old referral url for subsequent visits from a user.