I have never used the Facebook Comment piece of a site for one reason: I don't want all the people reading THAT site to have a link right to my Facebook page. Under normal circumstances, the chances of some random stranger getting to me Facebook page are pretty slim. But if I comment on some article with Facebook, my real name is right there with a link to my page. The last thing I need it for some nut job to take issue with something I said and follow that link.