I've been noticing the different number of stars and it seems that at a certain point you can change your little description-thingy. (Currently I'm a "I'm Not Obsessed!" Can somebody explain how this works? I'm really kind of lost.
Every certain amounts of posts will add stars on to your count. After 1000 posts you can change your member title (the "I'm Not Obsessed!" part). 3000 posts will make you a Supermember. Hope that helped.