I put the URL to share as my Facebook Page's URL (http://www.facebook.com/TourKick).
I only allowed the Facebook share (not Twitter, LinkedIn, or G+).
The Social Marketing link worked (pop-up) but I already liked the URL so it wouldn't let me click anything after it made me login to Facebook, so the plugin "doesn't work" in my opinion. Maybe I'm using it differently than it was initially designed, but I'd like it to work this way.
And regarding links other than FB Pages, maybe it would work the same way - to where someone could only get the asset once. I'm not sure.