I'm not sure what you mean but every inch lift something in my opinion,
if you put a helicopter on a scale, you read the weight, then you raise collective a few inches, that might not be enough to lift the entire helicopter off the ground, but sure you'll read less weight than with the collective full down.
Is that what you meant?
If you meant the actual scale from 0 to 12 then you're right, I never saw the MAP gauge displaying 0 anyway...