smoke = smokescreen Think of someone that is totally useless, but manages to convince others by his words and actions that he is useful. He's selling smile.

I agree with Eliot - smoke is not something you can package and sell, so whatever that person is selling, it's not real... just talk (viz. "smoke and mirrors"). See if that fits the context of where you found the phrase.

It means what he's saying does not have any values or his promises are empty.

This is an idiom, which means to cheat

Probably selling marijuana ( 'smoke' is the street name of marijuana).