Frequency

Frequency is the average number of times each person has seen your ad over a set period, worked out as impressions divided by reach: the total times your ad was shown, divided by how many separate people saw it.

Say your ad was shown 30,000 times and it reached 10,000 people over the past week. Divide one by the other and your frequency is 3, which means the average person in that audience saw your ad three times. It is not a number you set anywhere; it is an outcome of how much you are spending against how big your audience is, and it climbs steadily the longer you keep running the same ad to the same people.

You want to watch this because it is your early-warning gauge for showing the same people your ad too many times. When you see frequency creeping up week over week while your results sit flat or start slipping, that gap is one of the clearest signals you will get that the audience is tiring of what you are showing them, which is what we mean by ad fatigue. Catching it in the numbers lets you refresh the creative or widen the audience before your cost per result really starts to hurt.

Here is the part people get wrong: there is no single correct frequency that holds true across every account, product and audience, so do not chase a target number someone quoted you at a conference. A cold audience meeting you for the first time behaves nothing like a warm retargeting pool that already knows your name, and both will sit at very different frequencies for perfectly healthy reasons. What matters is how your own frequency moves against your own cost per result over time.

Track frequency against your cost per result, and let that relationship, not a number someone handed you, tell you when to act.