How they relate
Impressions are always equal to or higher than reach. Divide impressions by reach and you get frequency: how many times, on average, each person saw it.
When reach matters
Reach matters when you want new people to discover you, like launching a product or entering a new market.
When impressions matter
Impressions and frequency matter when you want repetition, like reminding people who visited your site or reinforcing an offer before it ends.
Why Reach vs Impressions matters
Reading the two together tells you whether you're reaching new people or showing the same ad to the same people over and over, which often leads to ad fatigue.
Too many views, too few people
A campaign reported 500,000 impressions, but reach was only 50,000, a frequency of 10. Most of the audience had seen the ad many times and stopped responding. Broadening the audience lowered frequency and brought results back up.
Common mistakes
Reporting impressions as people
Impressions count views, not people. Saying an ad 'reached 500,000 people' based on impressions overstates its audience.
Ignoring frequency
High frequency on a small audience wears ads out fast. Watch it alongside results.
Treating either as the goal
Both measure visibility, not sales. Pair them with clicks, leads and revenue.
Where we work on this