re: That's the answer. And thanks all.
I hope I did not misinform you. I think that most trades do not go through the specialist. He is just there to increase volume of trades so that prices are not driven up or down so much because no one happens to want to make a trade on that day at that time.
Additionally, for his own personal reasons, the specialist needs to make a profit on his trades, just like anyone else who buys and sells stocks.