What it measures
CPM standardises impression-based advertising costs to the price paid for 1,000 impressions.
Your result—
CPM measures media cost rather than clicks, conversions or profit. Use it with outcome metrics when evaluating campaigns.
How CPM works
Formula
CPM = ad spend ÷ impressions × 1,000.
Use the result
Compare the metric over time or between campaigns using the same measurement basis.