the.com/reach

means The number of people who were exposed to something — not the number who absorbed, liked, or acted on it.

from From Old English 'ræcan', meaning to stretch out or extend, as a hand reaching for something. The physical sense of extending toward a thing slowly stretched (pun intended) into the abstract: reaching an audience, reaching a goal. Marketing borrowed the word precisely because it still carries that bodily confidence — as if exposure were the same as touch.