Glossary

CPM (Cost per Mille)

CPM (cost per mille) is the price for one thousand ad impressions. It's the standard buying unit for awareness and social campaigns, where you pay for visibility rather than clicks. CPM tells you how expensive it is to be seen by your audience.

Formula: CPM = Cost ÷ Impressions × 1000

How to read it

Rising CPM on Meta usually signals audience saturation or auction competition; narrower audiences and Q4 seasonality push it up. Compare CPM across ad sets to find the efficient audiences.

Where it misleads

A low CPM can simply mean low-quality inventory. Cheap impressions in placements nobody looks at are worth less than expensive ones in front of the right people.

Related terms

Impressions →

Impressions count how often your ad was displayed, regardless of whether anyone clicked or even consciously saw it. Every appearance on a search results page, feed, or placement counts once. Impressions are the top of the advertising funnel: without them, no clicks, no conversions.

CPC (Cost per Click) →

CPC (cost per click) is the average amount you pay for one click on your ad. It reflects competition for your audience: the more advertisers bid on the same keywords or users, the higher the CPC. It's the price tag on your traffic.

Frequency →

Frequency is the average number of times each reached person saw your ad: impressions divided by reach. It measures repetition: some repetition builds memory, too much burns budget and goodwill. Frequency is the early-warning metric for creative fatigue on Meta.

Metrics explained are nice. Metrics watched are better.

HeyMetrix monitors all of these across Google and Meta, with alerts and a nightly AI briefing.

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