Lead Source as Hidden Field

Our team is trying to identify which social pages leads click through to fill out a form.  Our understanding is that we can put the lead source field as a hidden field in the form and identify which social site to populate in the URL. 

For example: www.domain.com/landingpageURL.html?source=linkedin

Will this work, even if it's not a .com URL?  Other examples have shown it with a .com at the end.

We just wanted to be absolutely sure.

Thank you!