⚡ THE ESSENTIALS IN 20 SECONDS
- Reach: how many different people saw your ad.
- Frequency: how many times, on average, each one saw it.
- Impressions = reach × frequency.
- Too little frequency leaves no mark; too much tires people and wastes budget. The sweet spot depends on the goal and the format.
IN THIS ARTICLE
Two campaigns can have exactly the same impressions and totally different results. The difference is almost always in how they are distributed: many people a few times or few people many times. That is reach and frequency.
Reach and frequency: reach is the number of unique people exposed to an ad in a period; frequency is the average number of times each person saw it. Together they explain how impressions are distributed.
The basic formula
Impressions = reach × average frequency.
| Campaign (fictional) | Impressions | Reach | Frequency |
|---|---|---|---|
| A | 1,000,000 | 500,000 | 2.0 |
| B | 1,000,000 | 100,000 | 10.0 |
| C | 1,000,000 | 250,000 | 4.0 |
All three bought the same volume. A reached many people without repetition; B repeated too much to few people; C is better balanced for a consideration campaign.
Why balance matters
There is no universal magic number. It depends on the format, the product and how well known your brand is. What matters is measuring it and not leaving frequency uncontrolled.
How to control frequency
- Set frequency caps per person and per period (daily or weekly) in display and video.
- Rotate creatives to reduce fatigue.
- Exclude people who already bought, unless you are driving repeat purchase.
- Check frequency by audience: retargeting tends to pile it up.
Reach and frequency by goal
| Goal | Prioritize | Indicative frequency |
|---|---|---|
| Launch or awareness | Reach | Low to medium |
| Consideration | Balance | Medium |
| Retargeting and conversion | Controlled frequency | Medium to high, capped |
| Repeat purchase | Buyer audiences | Tied to the purchase cycle |
For the cost of that reach, see what is vCPM.
Common mistakes
- Looking only at impressions and not at reach.
- Not capping frequency in retargeting.
- Running the same creative for months.
- Judging a reach campaign by its immediate ROAS.
A typical case (fictional)
A pet brand saw good CTR on its display but sales were not growing. On review, 70% of impressions were going to the same retargeting audience with a frequency above 15. It set weekly caps, rotated creatives and opened category audiences. With the same budget, reach tripled and new-to-brand customers grew.
If your budget stays flat but your reach grows, you are buying more potential customers with the same money.
How to measure whether it worked
For reach campaigns, look at metrics that reflect medium-term effect: brand searches, new-to-brand customers and incremental sales. To go further, use incrementality tests as I explain in what is iROAS.
Checklist
- Report reach and frequency, not just impressions.
- Frequency caps on display and video.
- Creative rotation every few weeks.
- A clear goal per campaign.
- Effect metrics: brand searches and new-to-brand customers.
- A frequency distribution report, not just the average.
Reach and frequency in video and CTV
In video, and especially in connected TV, reach and frequency become even more important because each impression costs more. The same household can see your ad on the TV, on a phone and on a laptop, so always ask whether the platform measures frequency per person, per device or per household. That difference changes how you should read the report, and it can make two networks look very different when they are actually delivering similar exposure.
Quick glossary
- Unique reach: different people, with no repeats.
- Incremental reach: new people a network or format adds compared with what you already had.
- Frequency cap: the maximum number of exposures per person in a period.
- Frequency distribution: how many people saw the ad 1, 2, 3 or more times.
- GRP: a traditional TV metric that combines reach and frequency across a population.
One last tip: when you compare retail media networks, always ask for reach and frequency over the same period and with the same definition. That way you will know which one gives you more new people for every dollar you invest.
Agency secrets about reach and frequency
What I apply on large accounts:
An average of 4 can hide many people at 1 and a few at 30. Ask for the distribution.
Video and display behave differently; do not use the same cap for everything.
Before adding a new network, ask how much new reach it brings and how much overlaps with what you already have.
Budget goes further when you stop paying twelve times to reach the same person with the same message.
I’m Alonso Jiménez, a Retail Media account director. I manage campaigns on Amazon, Walmart, Target, Instacart and Mercado Libre every day, for brands in the US, Mexico and Latin America.
Frequently asked questions
What is reach in advertising?
The number of unique people who saw your ad in a period.
What is frequency?
The average number of times each person saw your ad.
What is the ideal frequency?
There is no universal number; it depends on the format and goal. Measure it and cap it to avoid fatigue.
How do they relate to impressions?
Impressions = reach × average frequency.