When using Facebook Sharer, Facebook will offer the user the option of using 1 of a few images pulled from the source as a preview for their link. How are these images selec
This is what worked for me: I placed the desired thumbnail image on the page right after the tag and making it too small to see..
I have not tested it with height 0 and width 0 but it probably will still work.. This does not guarantee the user will select this image..
ALSO it seems like Facebook caches the thumbnails on your page and doesnt always check it for new ones.. try adding this to another page on your site and you'll see that it works.