Marketo's URL Builder - Does it only work on pages with forms?

[Anonymous]

I have a questions about when Marketo's URL builder will work or not. I have a landing page with a form that is URL defined to populate lead source. We sponsored a post on LinkedIn that drove people to a video/summary page and then had a link to the landing page with a form. Because the URL was for the summary page, the info for lead source doesn't populate when someone goes to the form page.  

In order for info like lead source to be defined my Marketo's URL builder, can you only send people to a page with a form? 

*The landing page form is currently a form 1.0 

[Edward_Masson]

you tend to have the required tracking fields as hidden on your form, so when they submit the form the URL with your values will get passed through.

[Anonymous]

I have lead source as a hidden field that's default value is Organic, but in cases when we advertise it would be URL defined as Paid Search or Display Ad.