Facebook Comments is an extension for Magento. This one allow to integrate Facebook.com Comments Widget into your store. In a few minutes you can easy create section with comments on each product page of the your store.
To install Facebook Comments at the Product page of your store you should: open the ///template/catalog/product/view.phtml file, which has your_skin as the name of your current store skin and your_locale as your current locale. If you haven't ever changed your store's skin or locale, use the default value for your_skin and your_locale.