When you make a post in a thread that you didn't start, you will earn .25 stars for that post. If you make a post in a thread that you did start, then you won't get any stars for that post. Instead, as the thread starter, you will receive 0.10 stars for each post that is made in your thread. So if your thread has 10 post that are not made by you, you will earn 1 full star. 0.10 x 10 = 1