I think it means: - Basically 'smooth operator' means 'a person who knows how to swim with the tide', or - 'a man of with a polished and winning personality who has amatory success with women', or - people who are skilful at achieving what they want, often in a slightly dishonest way. ex. He is a smooth operator. Don't underestimate him. Hope this could help.

Someone who displays great ease at getting what they want (usually by being slick...) Can be used to refer to a guy who is a player.... as Sade once sang... http://youtu.be/tY-H0ce6wkw

a smooth operator= a person who relies on charm to get what he/she wants