Cost Per Mille (thousand) — the price an advertiser pays for 1,000 ad impressions.
Impression
A single instance of an ad being displayed to a user, regardless of whether they interact with it.
Viewable Impression
An impression where at least 50% of the ad is visible on screen for at least 1 second (IAB standard).
eCPM
Effective CPM — normalizes revenue from different pricing models (CPC, CPA) into a CPM equivalent.
Fill Rate
The percentage of available ad inventory that is actually sold and filled with ads.
Real-World Examples
Example 1
Facebook Campaign
Spend: $2,500, Impressions: 420,000
CPM: $5.95. At 1.2% CTR, that is 5,040 clicks at $0.50 CPC equivalent.
Example 2
Display Network
Budget: $10,000, Target CPM: $3.50
Expected impressions: 2,857,143. At 0.1% CTR: ~2,857 clicks.
Average CPM by Platform (2024)
Platform
Average CPM
Typical CTR
Effective CPC
Facebook/Meta
$5-$15
0.9-1.5%
$0.50-$1.50
Google Display
$2-$5
0.1-0.3%
$1.00-$3.00
YouTube
$6-$15
0.5-1.0%
$0.10-$0.30 (view)
LinkedIn
$25-$60
0.4-0.8%
$5-$12
TikTok
$3-$10
1.0-3.0%
$0.20-$0.80
Understanding CPM Advertising
When CPM Makes Sense
CPM pricing is ideal for brand awareness campaigns where the goal is maximum visibility rather than direct conversions. If your primary metric is reach and frequency, CPM lets you predictably budget for eyeballs. It is less effective for direct-response campaigns where CPC or CPA pricing aligns costs with actual user actions.
Optimizing Your CPM
Lower CPMs come from better audience targeting (less competition for niche audiences), higher ad relevance scores, optimal ad placements and formats, and testing creative variations. A/B testing can reduce CPMs by 20-40% by finding which creatives the platform algorithm favors for your audience.