Why cost per mille (CPM) matters to a first-time founder
Cost per mille (CPM) helps founders compare the price of buying advertising exposure across campaigns and publishers. It says nothing by itself about attention, clicks, or sales. A low CPM may reflect cheap but irrelevant inventory, while a higher CPM can be worthwhile if it reaches the right audience.
Examples of cost per mille (CPM)
A campaign costs ₦900,000 and serves 300,000 impressions. CPM is (₦900,000 ÷ 300,000) × 1,000 = ₦3,000. If it reaches 100,000 people, each person sees the advert three times on average. CPM still uses impressions, not unique people, so it should not be described as cost per thousand people reached.
Common misunderstanding
The “M” in CPM comes from mille, meaning one thousand. An impression is a recorded display, not proof that a person noticed the advert. Platforms define viewability, invalid traffic, fees, and measurement differently. CPM can be a pricing model or a calculated comparison metric even when billing uses another basis.
When to use it
Use CPM for awareness campaigns, media planning, and comparing impression costs on a consistent basis. Pair it with reach, frequency, viewability, audience quality, and outcomes. If the goal is leads or sales, work through to cost per useful action instead of declaring success because impressions were inexpensive.