CPM is the oldest unit of account in digital advertising and still the one most publishers get quoted at. It is also the number most often misread, because the CPM an advertiser pays and the eCPM a publisher banks are two different figures measured from two different sides of the same auction. This guide defines both, shows the arithmetic, explains what an ad exchange does to the price in between, and sets out which levers actually move the result for a browser-based game or web publisher.

What is CPM?

CPM is the cost an advertiser pays for 1,000 ad impressions. The letters stand for cost per mille, from the Latin mille for a thousand, and the model prices reach rather than outcomes: the advertiser pays when the ad is served, regardless of whether anyone clicks it. CPM is the default currency of programmatic buying, which means most publishers are operating in a CPM world whether or not they ever negotiate a rate card directly. Two details matter more than the definition. First, CPM is a price, not a performance metric — a $12 CPM on inventory nobody sees is worth less than a $4 CPM on inventory that completes. Second, the definition of an impression varies by format and by counting rule. A banner impression typically counts on render; a video impression may count on start, on first quartile, or on completion depending on the network. When you compare two CPM figures, confirm you are comparing the same billable event before concluding one is higher than the other.

CPM vs eCPM: what is the difference?

CPM is what an advertiser pays per 1,000 impressions and eCPM is what a publisher earns per 1,000 impressions after every revenue source is blended together. The CPM is set on the buy side as a bid. eCPM is calculated on the sell side after the fact, working backward from realized revenue. The two rarely match, because the gap between them contains unfilled impressions, platform fees, discrepancies in counting, and any demand that was bought on a click or action basis rather than an impression basis. eCPM exists to solve a comparison problem. A publisher might run one placement sold at a fixed CPM, another filled by CPC demand, and a third on a revenue-share arrangement. Those three cannot be ranked against each other in their native units. Converting each to revenue per 1,000 impressions puts them on one honest scale, which is why eCPM — not headline CPM — is the metric to optimize. A studio that chases the highest advertised CPM and ignores fill rate usually ends up with lower total revenue than one that optimizes blended eCPM.

Related metrics: rCPM and vCPM

Two variants appear in network dashboards. rCPM (revenue CPM) is used by some platforms as a synonym for eCPM, expressing publisher revenue per 1,000 impressions. vCPM (viewable CPM) counts only impressions that met a viewability standard, so it prices attention rather than delivery. As advertisers buy more against viewability and completion, vCPM increasingly describes the real value of a placement — and formats that are inherently viewable, such as full-screen opt-in video, benefit structurally from that shift.

Metric	Whose number it is	What triggers payment	Use it for
CPM	Advertiser (buy side)	1,000 impressions served	Pricing reach, comparing placements before buying
eCPM	Publisher (sell side)	Calculated after revenue lands	Comparing formats, placements and countries on one scale
vCPM	Advertiser	1,000 viewable impressions	Judging whether inventory is actually seen
CPC	Advertiser	A click	Performance campaigns; convert to eCPM to compare
CPA	Advertiser	A defined action (signup, purchase)	Highest advertiser certainty, highest publisher risk

How to calculate CPM and eCPM

CPM and eCPM use the same arithmetic with different inputs. CPM = (ad spend ÷ impressions) × 1,000. eCPM = (ad revenue ÷ impressions) × 1,000. The only change is whose money is in the numerator.

• • CPM worked example. An advertiser spends $600 and receives 120,000 impressions. ($600 ÷ 120,000) × 1,000 = $5.00 CPM.

• • eCPM worked example. A placement generates $180 of publisher revenue across 30,000 impressions. ($180 ÷ 30,000) × 1,000 = $6.00 eCPM.

• • Converting a CPC deal to eCPM. 40,000 impressions produce 480 clicks at $0.25 each, or $120 of revenue. ($120 ÷ 40,000) × 1,000 = $3.00 eCPM. The deal was never priced in CPM, but it can now be ranked against the $6.00 placement above.

Those three figures are illustrative arithmetic, not market rates. Run the same conversion on your own reporting, segment it by placement and country, and the weak spots in a stack usually surface within an afternoon. A blended eCPM that looks mediocre frequently hides one strong format subsidizing several weak ones.

What is a CPM platform or a CPM ad exchange?

A CPM ad exchange is a real-time marketplace where publisher impressions are auctioned to advertiser bids, with the winning bid expressed as a CPM. A CPM platform is the broader layer around it — the ad server, SSP or mediation stack that packages inventory, attaches signals, enforces price floors, routes the request to demand sources, and settles on a per-thousand basis. Neither one sets a rate card. They set the conditions under which a price is discovered. That distinction is the practical one for publishers. Your realized eCPM is a function of three mechanical things: how many qualified bidders see each impression request, what signals travel with the request (geography, consent status, format, viewability history, placement context), and where your floors sit. A thin auction with two bidders produces a lower clearing price than a deep one with many, holding everything else equal. AppLixir operates as a programmatic rewarded video platform for web games and content publishers, running 100M+ monthly impressions through demand built for browser inventory, with a minimum publisher threshold of 5,000 DAU. For a wider view of how to evaluate any such layer, see the guide to choosing an ad monetization platform.

Mobile ads eCPM vs web eCPM: why the benchmarks do not transfer

Mobile ads eCPM figures describe an auction that browser traffic never enters. Unity Ads, AdMob, AppLovin and ironSource are app SDK networks: they serve inventory inside native iOS and Android builds, and they do not serve web. A WebGL or HTML5 build running in a browser cannot call those SDKs and cannot access that demand, which is the single most common reason a studio’s first web monetization attempt underperforms its mobile expectations. The detail of what does and does not work is covered in the breakdown of Unity rewarded ads and AdMob on WebGL. Beyond access, the demand itself differs. A large share of mobile rewarded eCPM is funded by user-acquisition budgets bidding for app installs, priced against a measurable install event and a device identifier. Browser inventory has no equivalent install conversion and no IDFA or GAID, so it is priced on consented contextual and audience signals instead. The result is a different clearing level with different drivers, and importing a mobile benchmark as a web target leads to the wrong conclusion about whether a placement is performing. Distribution platforms sit in a separate category again. Poki, CrazyGames and similar portals are complementary distribution — they bring players to a game and share revenue on their own terms. Running rewarded video on your own domain and in your own builds is additive to that, not a replacement for it. Most studios that monetize the web well do both: portal distribution for reach, their own rewarded placements for the sessions they control. For how those pieces fit, see the guide to browser game monetization.

What actually moves eCPM on a web game

Four levers explain most eCPM variance on web inventory: format, geography, consent, and viewability. Work them in that order, because the first one is structural and the rest are adjustments within it.

Format

Format sets the ceiling. Standard web display inventory typically clears in the range of $0.50–$2 CPM, while AppLixir delivers $4+ CPM on web rewarded video. The gap is not a pricing quirk — it reflects the difference between an ad a user learned to ignore and an ad a user explicitly requested in exchange for something. Moving a single high-traffic slot from passive display to opt-in rewarded video is the largest single eCPM change available to most web publishers. The format comparison is laid out in detail in rewarded video vs interstitial ads.

Geography

Advertiser demand concentrates in high purchasing-power markets, so the same rewarded placement earns materially different rates in tier-1 countries than in emerging markets. A blended eCPM across a globally distributed IO-game audience will always look weaker than a tier-1-only figure, even when every individual market is performing normally for its region. Segment by country before concluding anything about a placement. [DATA NEEDED: AppLixir eCPM by region, with window.]

Consent

Consent is a revenue lever, not only a compliance obligation. Impressions served without consent carry weaker targeting signals and attract lower bids, so the design of the consent prompt directly affects clearing prices in European traffic. AppLixir ships TCF 2.3 and GDPR compliance built in via Didomi, so the consent string travels with the bid request rather than being bolted on afterward. Framing the prompt around the value exchange — ads keep the game free — is the practical way to protect opt-in rates without a heavier tracking stack.

Viewability and completion

Viewability is the floor under every CPM, and completion is its rewarded-video equivalent. An opt-in video that loads instantly, plays to the end and closes cleanly produces exactly the signal demand partners pay more for over time. Preload the creative so the reward moment never stalls, cap frequency so the same player is not asked repeatedly within a session, and place units where they are genuinely in view. Sustained improvements here compound into the auction. The eCPM optimization guide for web games covers the tuning in depth.

Where rewarded video fits, and where it does not

Rewarded video is the strongest eCPM format on the web, but it is not a universal answer, and pretending otherwise produces bad integrations. It fits when the product has a natural reward moment: an extra life after a loss, a hint on a stuck puzzle, a doubled coin payout, a skipped wait timer, a continue at the end of a run. In those moments the player initiates the ad, so completion is high and the format does not feel like an interruption. It fits poorly in three situations. First, when there is no in-game economy or gated benefit to reward — a static content page with nothing to offer in return gives the player no reason to opt in, and a rewarded unit with a 2% opt-in rate contributes almost nothing regardless of its CPM. Second, when sessions are too short for a reward moment to arrive before the player leaves; fix the session design before adding the format. Third, below meaningful scale — AppLixir’s minimum threshold is 5,000 DAU, and under that level most publishers get more from improving retention and traffic than from re-engineering a monetization stack. Where rewarded video does fit, the honest framing is additive. It sits alongside whatever display, portal distribution and in-app purchase revenue a studio already runs, usually taking the one or two highest-intent moments in the session rather than replacing the whole stack. Studios that treat it that way tend to protect retention while lifting blended eCPM, which is the outcome that matters. For revenue mechanics in practice, see how much rewarded video ads pay on web games, and for the integration path, the HTML5 rewarded video SDK guide.

FAQ

What is the difference between CPM and eCPM?

CPM is the price an advertiser pays per 1,000 impressions, set on the buy side as a bid. eCPM is what a publisher actually earns per 1,000 impressions once CPM, CPC and CPA demand are blended and unfilled impressions are included, calculated as (ad revenue ÷ impressions) × 1,000. Advertisers manage CPM; publishers should manage eCPM, because it is the only figure that puts different deal types on one comparable scale.

What is a CPM ad exchange?

A CPM ad exchange is a real-time marketplace that auctions publisher impressions to advertiser bids priced per 1,000 impressions. It does not set a fixed rate; it discovers a clearing price based on how many qualified bidders compete for the request and what signals accompany it, including geography, consent status, format and placement context. Deeper competition on the same impression is what raises the realized price.

Do mobile ads eCPM benchmarks apply to web games?

No. Unity Ads, AdMob, AppLovin and ironSource are app SDK networks that do not serve web inventory, so their published eCPM figures describe auctions a browser game cannot enter. Mobile rewarded eCPM is also supported heavily by app-install demand and device-level identifiers that have no browser equivalent. Use web-specific figures when setting expectations for an HTML5, WebGL or IO game.

Which ad format has the highest CPM on the web?

Opt-in rewarded video is the highest-paying standard web format, because the user requests the ad and watches it to completion rather than ignoring it. Typical web display inventory clears roughly $0.50–$2 CPM, while AppLixir delivers $4+ CPM on web rewarded video. The premium depends on the placement having a genuine reward moment attached — a rewarded unit with nothing to offer in return will not earn it.