It's to see how many people bother to check if their question has been asked and answered before. You are person number 82 squllion to ask this question, and so win a prize. If however, you had read just one of those other questions (at that point when you click submit, and AB shows you a list of similar questions and says "do you still want to post.."), you'd already know the answer!
Actually I did check if there was another question the same and this question didnt come up..some about green tyres, green eggs and green energy...but not green user names...so there, Mr Grumpy.