What Is CPM (Cost Per Mille)?
CPM is the cost per thousand impressions. It's the standard pricing metric for brand awareness advertising.
Key Takeaways
- CPM = (Total Ad Spend ÷ Total Impressions) × 1,000.
- CPM measures the efficiency of awareness-stage advertising.
- Lower CPM doesn't always mean better — audience quality matters more than volume.
What CPM is
CPM stands for Cost Per Mille — mille being Latin for thousand. It is the cost of showing your advertisement 1,000 times (1,000 impressions). If you spend £1,000 and your ad is shown 200,000 times, your CPM is £5. CPM is the standard pricing metric for display advertising, video advertising, and social media reach campaigns.
When CPM is the right metric
CPM is most relevant for awareness campaigns where the goal is reach and frequency rather than immediate conversion. Brand-building, new product launches, market entry, and retargeting reach are all contexts where CPM efficiency matters. For conversion-focused campaigns, CPC (cost per click) or CPA (cost per acquisition) are more meaningful.
CPM benchmarks
CPMs vary widely by platform and audience. LinkedIn (B2B) typically runs £10–30 CPM. Meta (B2C) runs £4–15 CPM for broad audiences, higher for precise targeting. Google Display runs £1–10 CPM. Connected TV advertising runs £15–40 CPM. These ranges fluctuate with market demand — Q4 sees significantly higher CPMs in most markets as competition for ad inventory intensifies.
Audience quality vs CPM efficiency
A £3 CPM reaching a broad, low-intent audience may produce worse business results than a £20 CPM reaching a precisely targeted, high-intent audience. The efficiency metric that matters is CPM relative to the revenue or attention it generates — not CPM in isolation. Always assess reach campaigns by downstream metrics: are CPM improvements producing corresponding increases in consideration and conversion?