How to Add Disqus Comment System in Your WordPress Site
In one sentence, you should use it because it offers many features good for user experience. And user experience is very important for site owners. The reason we use a great theme with a great logo, add many useful widgets, make our site colorful and add high-quality content, is because this stuff improves the user experience. With Disqus commenting system, you replace WordPress default commenting system with many useful features. Here is a quick list of Disqus commenting features:
Comment Syncing copies comments made in Disqus to your WordPress installation as backup in case you ever decide to switch back to native WordPress comments. Syncing is not enabled by default. To enable syncing, you’ll need to set it up either by creating an API application (follow instructions here) or via Automatic Installation in the plugin.