I have a thread that is getting quite a bit of attention that I would like to make sure Facebook is posting a decent thumbnail for. It is an embedded vimeo video with no other images in the post so I added a thumbnail from the video so that FB would grab it as the image.
The problem is that FB grabs that image if I link to any post in the thread OTHER than the first post or the main thread link.
If I post this to FB, it posts the thumbnail:
But if I post the main thread URL, it posts no thumbnail.
Same problem if someone clicks the Facebook Like button.
Any ideas on how to fix this, even if it's just a one time fix for this particular thread?