It means that you are winning!

It means that everything that you are doing is turning out to be very successful. Let's say that Tom sees a pretty girl he does not know. He wants to take her to the movies, but he is afraid that she might say no. But he goes over to her and starts talking. And he and the girl talk and talk and talk. And she smiles and laughs and smiles and laughs. Tom's friends see all of this activity and say to themselves: "Wow! He's on a roll! She is probably going to say yes."

like ,you are continuously doing things right