We use a ranking system for a bit of fun, gives you something to aim for and rewards you the more active you are. There is no real benefits to the system, it is about having a bit of fun.
You earn rank increases by being active, so that means logging on, interacting with the site and with members. For visiting profiles, liking posts, uploading videos and images. In fact anything you do that interacts with the chat helps you increase your rank.
You can see your rank by looking at your profile, or selecting the menu option in the Profile/Settings menu item.