Impressions

Impressions are the number of times your ad was displayed. Every time an ad appears on someone's screen, it counts as an impression, including repeat views by the same person. On Meta, an impression is generally counted the first time an instance of an ad appears on screen, regardless of how long it stays visible or whether anyone engages with it.

Impressions versus reach

• Impressions: total number of times the ad was shown.
• Reach: number of unique people who saw it.

If 1,000 people each see an ad three times, that is 3,000 impressions and a reach of 1,000. The ratio between them is frequency.

Why impressions matter

Impressions are the foundation for several other metrics:

• CPM = (spend ÷ impressions) × 1,000
• CTR = (clicks ÷ impressions) × 100
• Hook rate = (3-second video plays ÷ impressions) × 100

Because so many ratios use impressions as the denominator, it is worth understanding what is and is not being counted.

Limitations

• An impression does not mean someone looked at the ad. People scroll quickly, and an ad can appear briefly without being noticed.
• Impression counts are not directly comparable across platforms, because each defines and measures them differently.
• Different placements may receive very different levels of attention per impression.

In practice

Use impressions mainly as an input to rate and cost metrics, and judge performance on outcomes such as CPA and ROAS rather than on impression volume alone.