Reach counts different people. If the same person sees an ad five times, that counts as one in reach and five in impressions. The distinction matters because repetition and unique audience are different goals.

Advertisers with a broad message, like a brand launch or a public health campaign, prioritize reach. They want as many different people as possible to see the message at least once. Frequency-focused campaigns, by contrast, target a smaller group with repeated exposure.

Reach considerations

• Unique users versus total impressions
• Overlap between channels
• Deduplication across devices
• Incremental reach as budget grows

Adding budget eventually stops buying new reach. The audience gets saturated, and extra spend only increases frequency. Planners watch for that point and shift to other channels.