Right now, when I share my listing page on Facebook, the preview says
"Freemarket.com | Buy and Sell websites, domains, or web businesses."
It would be better when on Facebook, it would say about what I am selling, perhaps something like
"Website for Sale - DreamWhipper.com, bid starts at $500"
or something like that. It makes more sense to share that on Facebook. One company that does this well is TeeSpring.com.
I am sure you know what I mean. And I am sure you know how to implement this. All the best with FreeMarket.com.