They are added to your information as you reach various milestones determined by the number of posts.
New member upto 50
Bronze over 50
silver 500
Gold 2500
Platinum 5000 (I probably got the numbers wrong;don't worry though If I did someone will be along right smart and correct the info)
Something like that. It doesn't mean much except how many times you've posted. It's no guarantee of any quality of help or anything like that. You'll see after a while that just because someone has a gazillion posts credited to them they aren't necessarily a helpful member on the forum. Conversely I've been helped by someone with only a few posts. So there you go. No real benefit. No Cakewalk discounts or anything. Doesn't really mena much. Discussion often suggest that the star rating system be done away with entirely. All the best.