Quick answer
CPM (cost per mille) is the price of one thousand impressions. It is the unit for buying reach and brand placements, where the goal is to be seen rather than clicked, and the first number compared across channels.
CPM
DefinitionAn impression is one serving of an ad; CPM prices a thousand of them. It is how display, video and most native inventory is bought, and it makes channels comparable on one axis: what it costs to put a message in front of a thousand people. Audience quality, viewability and format decide whether that is a bargain or a waste.
Also called: Cost per mille, Cost per thousand impressions.
How is CPM calculated, and what counts as an impression?
CPM is the cost divided by impressions, times a thousand: a campaign that cost 2,000 for 400,000 impressions ran at a CPM of 5. The catch is in the denominator. An impression is counted when the ad server delivers the ad, which includes below the fold, in background tabs and to crawlers, unless the seller counts only viewable impressions (half the ad on screen for a second).
Always ask which impressions a CPM is quoted on. The same campaign has a lower CPM on served impressions than on viewable ones, and a lower one again on impressions a person actually looked at, which no one quotes because no one can count it.
Why are developer CPMs higher, and are they worth it?
Developers are a small audience with large budgets behind them, hard to reach because they block ads and read in a few places, and expensive to reach because every developer platform knows it. A developer platform CPM is several times a general-audience one.
The comparison that matters is cost per developer who engaged, not CPM. A thousand impressions on a general network might contain fifty developers, forty of whom block the ad; a thousand on a developer platform contains a thousand developers reading the feed the ad sits in. The "expensive" CPM is often the cheaper way to reach one engineer.
Common mistakes
- Comparing a served-impression CPM with a viewable-impression one.
- Choosing the channel with the lowest CPM and the fewest developers.
- Treating a benchmark CPM as a price you are owed.
- Buying CPM for a performance goal and then reporting on clicks you did not optimise for.
The number to carry into the meeting
- Cost per activated developer, by channel, over the campaign month. CPM is an input to it; it is the output.
When should you buy on CPM rather than CPC or a plan?
- CPM when the goal is to be seen by the right audience repeatedly: brand presence, launches, category ownership. You pay for reach and manage frequency.
- CPC when the click is the goal and you can measure what follows it, and the platform's audience is already right (search intent, a niche community).
- A managed plan when expertise matters more than control: the platform's team sets targeting, shapes creative and paces delivery, and you buy an outcome for a month rather than units.
Many developer campaigns end up on a plan or a CPM and judge results on activations, because developers do not click much and convert later.
How do you compare CPMs across channels fairly?
Normalise three things before comparing: whether the impressions are served or viewable, who the audience is (verified developers, or a category called "technology"), and what you get per impression (a banner glanced at, or a card read in a feed). Then convert to cost per engaged developer using each channel's reads or clicks from real developers.
Published benchmarks help as a sanity check and mislead as a target. A benchmark CPM for "B2B display" says nothing about a developer feed; a benchmark for a developer newsletter says nothing about yours until you have run one.
On daily.dev
How it works on daily.dev
daily.dev Ads is not bought by CPM: it is one managed monthly plan in three sizes, quoted per company, with the reach it buys stated in the proposal. Delivery is reported in impressions, reads and follows.
Explore my optionsCPM vs CPC
| Capability | CPM | CPC |
|---|---|---|
| You pay for | A thousand impressions | Each click |
| The risk of being ignored sits with | The advertiser | The platform |
| Suits | Reach, brand presence, always-on | Measurable visits, search intent |
| Watch out for | Cheap impressions nobody looks at | Cheap clicks that never convert |
| On daily.dev | Neither: one managed monthly plan, quoted per company; delivery reported in impressions, reads and follows | Clicks reported alongside reads, follows and pixel conversions |