I think that at some point Facebook made changes on their end that effect how <fblike></fblike> works. It used to be that this would allow a campaign to be shared in the newsfeed on Facebook. Now it just appears as a Like on a Facebook user's timeline. Is there any other code snippet available that would allow a campaign to be shared in the Newsfeed?
By all means you can investigate using sharer.php, but generally we don't recommend its use, as Facebook may disable it at any time.
Sorry for this trouble, but we'll keep you posted if we say create a tag for sharing campaigns.