Check the Unit code is correctly embedded onto your site by enabling the "Test Ad Units" function and be sure your Site is active.
Correctly embedded Ad Units will produce a demo ad when "Test Ad Units" is enabled. If no video appears, try refreshing the page and confirm the compatibility with your site's platform (Wordpress, WIX, etc) or Ad Manager (DFP). Until your site is approved, no revenue earning advertisements will appear on your site. You can enable the test mode to preview Ad Unit placement prior to site approval.
Please note that Ad Units embedded in the <head> of your site may not produce a demo ad.
If your Ad Unit is not earning revenue yet, or no video appears on your site may be that the visitors to your site are not within the campaign target audience.
Learn which ads will be visible on your site.