CPM

What CPM is

CPM (cost per mille) is the cost of one thousand ad impressions: spend divided by impressions, times 1,000. It is the lingua franca of media buying — display, paid social and video are all bought and benchmarked in CPM — which is exactly why it migrated into influencer marketing as the quickest way to compare a creator's price with other media.

Impressions, reach and eCPM

An impression counts one content delivery; reach counts unique people. A follower who sees a Reel three times is three impressions but one reached account. CPM conventionally uses impressions; computed on reach it becomes a different (higher) number, so any comparison must fix the basis first. eCPM ("effective CPM") normalizes campaigns that were not bought on impressions into the same unit after the fact.

CPM in creator pricing

Dividing a creator's fee by expected impressions (times 1,000) yields the implied CPM of the offer — a sanity check, not a valuation. Expected impressions are best estimated from the creator's recent average views for the same format, not from follower count. Implied CPMs in influencer marketing routinely exceed paid-social CPMs, and often legitimately so: creator content carries trust, native context and a reusable asset. The comparison flags outliers; it does not decide fair price. Benchmarks vary so strongly by platform, market, niche and season that any fixed number would mislead — build internal benchmarks from your own closed deals instead.

Limits

A cheap thousand impressions is not automatically good marketing: an impression is delivery, not attention, and certainly not intent. Low-CPM inventory in front of the wrong audience is wasted budget, while a high-CPM niche creator with exactly the right audience can be the best buy on the plan. CPM also says nothing about outcomes — pair it with engagement rate for attention quality and with ROAS where sales are trackable.

In agency practice

Agencies use CPM in two directions: defending creator prices to brands ("the implied CPM sits inside your paid-social range — and you keep the content") and spotting mispriced offers when building campaign line-ups. An internal CPM benchmark per platform and format, refreshed from actual campaign results, turns pricing debates into short conversations.