Reach vs. Impressions on Facebook
Reach is how many people saw a post; impressions is how many times it was shown, including repeats.
What it means
Reach counts unique people. Impressions count every time the post appeared on a screen, even if the same person saw it five times. A post can have 1,000 reach and 3,000 impressions if people scrolled past it, then saw it again later in their feed.
Why it matters
A high impressions number with flat reach usually means the same small audience is seeing your content repeatedly, not that you're growing your audience. If you're trying to reach new people, reach is the number to watch, not impressions.
ask datanephew
Which number should I actually care about?
It depends on your goal — ask datanephew to explain both for your recent posts and which one matters given what you're trying to do, whether that's growing your audience or reinforcing an existing one.
Why do my impressions keep going up but my reach is flat?
Ask datanephew to check whether the same audience is seeing repeat impressions — that's the usual explanation, and it can confirm it from your Page data.