Disqus Commenting - Plugin
Your site is equipped with an off site commenting system. What that means is that all comments on your site are handled by Disqus and has the following advantages:
Comments become more like live discussions with realtime posting and updating and offers a fast, intuitive experience.
Full integration with Facebook, Twitter, and more. Let people login, comment, and share using social services they already use.
Disqus reaches 200 million people every month across half a million websites and communities on the web. Keep the conversations lively by connecting your audience with the millions of others already on Disqus.
You'll need to sign up for an account (it's free) and configure the plugin.
This video will show you how: