Understanding reach metrics

On-site performance reporting includes two audience metrics — Reach and Impression Frequency — so you can see how many unique shoppers your campaigns reached and how often, on average, each one saw your ads.

Rolling out soon

Reach and frequency metrics are rolling out gradually. If you don't see them yet in your on-site reporting, contact your Epsilon representative to confirm availability for your retailer.

Overview

Impressions tell you how many times your ads were shown, but not how many people saw them. Reach and frequency close that gap:

• Reach answers "how many unique shoppers did I reach?"

• Impression Frequency answers "on average, how many times did each of those shoppers see my ad?"

Together with impressions, clicks, and conversions, these metrics help you judge whether a campaign is building broad awareness across many shoppers or concentrating exposure on a smaller audience.

What each metric means

Reach is the number of unique users who were exposed to your ad at least once in the selected period. Someone who sees your ad five times still counts as a reach of one.

Impression Frequency is the average number of times each unique user saw your ad in the selected period. It is calculated as:

Impression Frequency = Impressions ÷ Reach

For example, 10,000 impressions delivered to 4,000 unique shoppers gives an impression frequency of 2.5 — on average, each shopper saw the ad two-and-a-half times.

Reach is measured using an estimation method designed for large audiences, so it is a highly accurate approximation of unique users rather than an exact head-count. This is standard for audience reach reporting and keeps the numbers fast and consistent across large date ranges.

Reading the numbers

Metric	Format	What a higher number tells you
Reach	Whole number	Your ads reached more unique shoppers
Impression Frequency	Up to 4 decimal places	Each shopper saw your ad more often (exposure is more concentrated)

Where you'll see reach and frequency

On-site performance dashboard — All Campaigns table

Reach and Impression Frequency appear as columns in the All Campaigns table on the on-site performance dashboard. Scroll right to see them alongside your other KPIs, or export the table for deeper analysis.

Single campaign — History breakdown

When you open a campaign and view its History breakdown on the Performance tab, Reach and Impression Frequency are shown per day so you can track how your reach built over the life of the campaign.

Reach metrics are calculated daily and are not available in the hourly view. If you switch the history breakdown to hourly grouping, the Reach and Impression Frequency columns are hidden.

Brand Page campaigns

Brand Page performance reporting shows Reach alongside Views and Unique views, giving you a unique-audience view of how your brand pages performed. Impression Frequency is not shown for Brand Page campaigns.

Key Information

• Reach and Impression Frequency update once a day. Unlike impressions, clicks, and conversions — which refresh hourly — reach-based metrics are recalculated daily. Column headers show an "Updates daily" note with the last-updated time, and the dashboard displays a "Some metrics update daily" message.

• Totals rows show a dash (—) for these metrics. Reach and frequency can't be meaningfully added up across different campaigns or across days, so the summary/totals row intentionally leaves them blank rather than showing a misleading total.

• Metrics respect the retailer's time zone. Like all reporting in the new interface, the "day" used for reach is based on the retailer's configured time zone. See Understanding reporting data delays and time zones.

• Hourly view excludes reach. Because reach is a daily calculation, it appears only in daily (and Brand Page) views, not hourly breakdowns.

Why can't I view reach across campaigns?

Reach counts unique shoppers. The same shopper can see ads from several of your campaigns, so adding each campaign's reach together would count that shopper more than once. For the same reason, a single campaign's daily reach figures don't sum to its total reach for the period. To see reach for a wider set of campaigns or a longer period, select that scope directly in the filters rather than adding the individual rows.

Best practices

• Use frequency to spot over-exposure. A steadily climbing impression frequency with flat conversions can signal that you're showing ads to the same shoppers repeatedly with diminishing returns. Consider broadening targeting or refreshing creative.

• Use reach to gauge awareness. When your goal is to introduce a product or brand to as many shoppers as possible, prioritise growing reach rather than piling more impressions onto the same audience.

• Compare reach and impressions together. High impressions with low reach means concentrated exposure; high reach with low frequency means broad but shallow exposure. The right balance depends on your campaign goal.

• Select the full date range you care about. Because reach is de-duplicated, always set the filter to the period you want to measure rather than summing shorter periods.

FAQs

What's the difference between impressions and reach?

Impressions count every time your ad was displayed, including repeat views to the same shopper. Reach counts each unique shopper only once, no matter how many times they saw the ad.

Why is my reach lower than my impressions?

That's expected. Because most shoppers see an ad more than once, reach (unique shoppers) is almost always lower than impressions (total views). The ratio between them is your impression frequency.

Why do Reach and Impression Frequency show a dash in the totals row?

These metrics count unique shoppers, so they can't be summed across campaigns or days without double-counting the same people. The totals row leaves them blank on purpose. Filter to the scope you want instead.

Why don't reach metrics update in real time?

Reach and Impression Frequency are recalculated once a day, so they can trail your hourly metrics by up to a day. Column headers show when they were last updated.

Why can't I see reach in the hourly history view?

Reach is a daily calculation, so it isn't available at an hourly grain. Switch the history breakdown to daily grouping to see Reach and Impression Frequency.

I don't see reach and frequency at all — why?

These metrics are rolling out gradually and may not yet be enabled for your retailer. Contact your Epsilon representative to confirm availability.