The plot of Sweet Smell of Success (1957) is as follows:

Press agent Sidney Falco is tasked by powerful columnist J.J. Hunsecker to break up his sister Susan's relationship with a jazz musician. Sidney resorts to unethical tactics, leading to Steve's career being ruined and Susan's disillusionment. Realizing the truth, Susan abandons J.J. and chooses a new life.

Why is it titled "Sweet Smell of Success"?