# Reach

> Reach is the number of unique people who saw your ad at least once.

Canonical: https://use-addy.site/glossary/reach
Last updated: 2026-10-26

Reach differs from impressions, which count every view including repeats. The two together give you frequency. Platforms estimate reach, so it is an approximation, not a head count.

## Related

- [Frequency](https://use-addy.site/glossary/frequency)
- [CPM (cost per mille)](https://use-addy.site/glossary/cpm)