You advertise on FB.
Your landing page has a video.
You don't want to show the buy button to FB.
LeadPages.net has a new template that allows you to do this in ...minutes.
Here's the landing page as FB and viewers see it.
It appears "harmless" like real content.
No buttons screaming BUY !!

In LeadPages, just set the time before the buy button appears.
For example, buy button appears only after 61 seconds:

Now when the viewer watched the video, a buy button appears after 61 seconds.

In LeadPages, it's called WEBINAR REPLAY 2.0