By using this Live URL setting, people who click on your links on Google Adwords or Facebook Ads will visit your landing page where an invisible field is pre-filled with where they came from. For example, you would make all of your Google Adwords links point to:

www.digitalpr.com.au?cpgn=adwords

Then the "cpgn" hidden field will be automatically populated with the word "adwords". When the user submits their enquiry using your seblod enquiry form, you will be able to track which inbound marketing campaign they came from.