You are a mezzo poster, and you get more stars the more you post *points at own 9 stars*, they grow with your post count.
[quote1174421947==(e)= яiśκ]
How come next to my name there are two stars?
....because you have not yet posted enough to merit THREE stars :p

The more you access the forum the more stars increase. It doesn't say it anywhere, but if you look at a person's profile beside the "Rating" notation, it has something like "mezzo poster" or "forum Junky", etc. That translates to number of stars.
No, it was a good question, there is no possible way you could find out other than asking, or using abstract reasoning.