"This story has more sides to it than a rhombus in a kaleidoscope. Facebook is now offering any site the option to deploy Facebook's comments system, allowing posts to appear in a wall-like manner on the posting user's Facebook account, increasing web engagement all around."
Frankly it is better to make a comment on a social network than on a site itself. This site gets most of it comments on Twitter and Facebook and not on the blog. People want to comment in a shard space, so that others can join in.