A post’s reach refers to the number of users who have been exposed to it. While this is sometimes assumed to be equivalent to the number of people who saw a post, reach does not always consider users who have actually taken the time to read a post from users who have simply scrolled past it in their feed. However, unlike impressions, reach does not count the same user being exposed to a post more than once as discrete, i.e., as more than one user reached.
Reach is typically used as an indicator of audience size and brand awareness, with analytics tools distinguishing organic reach from paid reach when a post involves paid promotion.
