Definition

CPM (Cost per 1,000 impressions)

CPM is how much you pay for 1,000 ad impressions. Lower CPM means cheaper reach; higher CPM means more expensive reach.

What it means

CPM is a delivery cost metric: spend ÷ (impressions/1,000). It’s influenced by competition, audience size, seasonality, placement, and how platforms predict engagement. Creative affects CPM indirectly—engaging ads can sometimes earn better delivery economics.

Why it matters

  • CPM determines how expensive it is to reach your audience at scale.
  • A small CPM change can materially impact CAC when you spend heavily.

How to improve it

  • Improve creative engagement (strong hooks, clear structure, proof).
  • Test broader audiences and placements if you’re overly constrained.
  • Refresh creatives to reduce fatigue-driven delivery issues.

Common mistakes

  • Treating CPM as purely a bidding issue and ignoring creative.
  • Comparing CPM across completely different audiences/placements.

Related terms

Apply this with free tools

Use August Ads tools to generate better hooks and scripts, then test variants: