You went to a party; there you saw a beautiful girl. You went to her and said, "I am a very rich man. Marry me." In reply, she introduced you to her husband.
This is called "Demand and Supply Gap".
You went to a party; there you saw a beautiful girl. You went to her and, before you could say that I am very rich, marry me, she turns and looks towards you. Oh, this is your own wife.
This is called "Competition which is eating your share from the market".