Reach
Reach is the number of unique people who saw your ad at least once during a given time period.
What it actually means
Reach measures distinct individuals, making it the people-level counterpart to impressions. Together they define frequency: impressions divided by reach. Reach is capped by the size of your target audience — you cannot reach more people than exist in your targeting. For local businesses with a small geographic radius, total available reach is finite, which is why scaling spend eventually just raises frequency instead of finding new people. Reach is the right metric for awareness goals and for diagnosing whether a campaign has saturated its audience. It does not measure interest or action, only exposure.
Knowing your maximum reach within a 10-mile radius tells you the ceiling on a local campaign. Once you have reached most of your area, growth comes from better offers and creative, not more budget.
Related terms
An impression is counted each time your ad is displayed on screen, regardless of whether the same person sees it more than once.
Frequency is the average number of times each person saw your ad, calculated as impressions divided by reach.
An audience is the defined group of people your ads are eligible to reach, built from location, demographics, interests, behaviors, or your own data.
Ad fatigue is the decline in ad performance that occurs when an audience has seen the same creative too many times.
Want this metric run for you?
Karbon Agency runs Meta, SEO, and landing pages for local businesses — and shows you every metric, live.