Not for nothin', but...

By Richard K. Barry 

If you go online and look for a definition of the term "not for nothin'," you'll come up with a pretty broad range of opinions. About the only agreement, I think, is that it's generally thought to originate in the Northeastern United States or perhaps more specifically New York City and is working class slang.

In general terms, it's a phrase that introduces a comment or observations of one sort or another.
As for what people think it means, here are just a few examples, some of which are related, mostly, but maybe a little different from each other:

• "Not for nothin'" is used to soften the blow of something that would normally be offensive or come on too strong.
• Common big house or camp preface to a piece of advice or a warning. Its use is supposed to imply the speaker is neither bossing around nor threatening the hearer, only offering sage advice or a pithy observation. In practice, however, it is often used immediately before a verbal threat to another inmate. 
• Phrase meaning "what I'm about to say is important." That is "I'm not saying this for my health..."
• Used as an introductory phrase to indicate that the principle phrase which follows is intended neither to be commanding nor officious, but simply as friendly advice or constructive observation.
• Colloquial, inverted way of saying, "for good reason," to emphasize a point. "Not for nothing is Paris called the City of Lights." Used extensively in English literature, including C.S. Lewis, Samuel Butler, and Jack London.
• This is an old Italian expression "non per niente" and its true meaning is: not that I have anything to gain by it – but it is what he said or meant or did... and so on. Basically, I am relating this, believed to be true... believe what you will... relating without responsibility.

The only thing I know about the phrase is that Silvio Dante, a character in The Sopranos, played by Steve Van Zandt, sometimes uses it to preface advice he wants to give to his mob boss, Tony Soprano, played by James Gandolfini.

In those contexts, here is what I think "not for nothin'" means:

What I'm about to say might be true. It might not be true. But if it is true, it could be important, so you might want to think about your options. But I'm not just saying it to hear the sound of my own voice (hence the "not for nothing," i.e., not for no reason at all). But if what I'm about to say offends you, remember that I'm just passing on what might be useful information, so don't shoot the messenger (literally).

So, I'm not saying this is the only context in which the phrase can be used, only that this is the sense in which I think it's used in The Sopranos, and it would seem to be pretty close to the last definition given above rendered in Italian as "non per niente."
Other opinions?

(Cross-posted at Lippmann's Ghost.)