What does "Move the Needle" mean? Definition or Meaning

Sometimes it helps to think literally. When you weigh vegetables on a grocery shop scales, you would see “the needle” move, wouldn’t you? But if you didn’t buy anything on it, the needle doesn’t move. In the business world, there could be times when you put in the metaphoric vegetables but the needle still doesn’t move meaning, it fails to generate a response.

For example…

Let’s say Kirsty’s Kreme Donuts started a marketing campaign that intended to educate people about her healthier donuts while trying to lure them from her more famous namesake. However, the marketing campaign failed to move the needle in terms of sales as the target wasn’t reached for several successive months. You could say Kirsty “pulled the plug” on the campaigns but it might suffice to say she stopped them.