The problem with the current commenting system as it is used on Facebook as well as other online platforms is that people first share a link to an external article to their preferred social network, then start commenting on it. — This way, the discussion is kept within a data silo, only available to a few friends or members of a certain group. A discussion like this has a pretty short life cycle as it fades away into the Facebook timeline of a certain user or page. The discussion gets separated once another friends shares the item on his own — comments are not copied over, or better, referenced to the original url of the shared article.