Any updates on URL parameters? Can I still only use them through form submission? I've finally got the team adding them to every single email and I'd like a scalable/efficient way to track sources of all clicks.
Agreed with Josh, you should use hidden form fields that pull in parameters and populate the source field.
You only need one global form though. Let the parameters do the work for you.
You can market to these leads by pulling in filled out form and querystring contains. This will allow you to seperate the various webinar you host.