One of my favorite WordPress plugin is Related Posts that, as the name suggests, displays links to other other articles on your your website that are contextually related to your current article.
If you are wondering how they are able to determine Related Posts in WordPress with such accuracy, here’s the secret revealed by the developer himself.
The plugin, is simple English, does a MySQL full text match against the post title, tags, categories and the post body. They are assigned weights and if the sum is greater than the threshold, that posts appears as a related posts.
Matt Cutts of Google also recommended that sites display related posts to help search bots discover deep content. Here’s the video: