Showing hands online & live

This question is do you ever show hands online or live? I used to never show winning hands, then I started too. Sometimes I would show I had the nuts and the player made a good fold. Now I am thinking what benefit do I really get showing hands???

Would really like to get some feedback on showing hands, do you do it or never do it?
What if a friend is in the hand, would that change matters?

I understand table image, the number of hands you played, etc, etc, but my question is really around do you show hands or not and if you do why?

Thank you