This is a simple web feature for keeping track of experience progress in RuneScape. Once you have created a profile (by simply searching for your name) your statistics data will be automatically grabbed once every 24 hours so you can keep track of how you're doing. You can also manually update it whenever you wish.
If you change your display name, your profile will stop being tracked. Click on the 'Change Name' link in the top corner to input your new name for the system to start tracking again.