- eCPM
- Effective cost per mille: what you earn per 1,000 impressions, whatever the advertiser actually paid for. Revenue ÷ impressions × 1,000.
- CPM
- Cost per mille: the price an advertiser agrees to pay for 1,000 impressions.
- RPM
- Revenue per mille: what you earn per 1,000 pageviews (page RPM) or sessions (session RPM), including pages that showed no ad.
- CPC
- Cost per click: the advertiser pays only when someone clicks. Common in search-style and contextual ads.
- CPA
- Cost per action: the advertiser pays when a user completes a sale, sign-up or other conversion.
- CPI
- Cost per install: what an app advertiser pays for each new install. It drives much of the demand in mobile game ads.
- CTR
- Click-through rate: clicks divided by impressions. Unusually high CTR is a warning sign for invalid clicks.
- Fill rate
- The share of ad requests that came back with an ad. Unfilled requests earn nothing.
- Show rate
- The share of loaded ads that were actually shown to a user.
- Impression
- One ad shown once to one person. The basic unit that most ad revenue is counted in.
- Viewability
- The share of impressions that were actually on screen: at least half the ad for at least one second for display, two seconds for video, under the MRC standard.
- ARPDAU
- Average revenue per daily active user: a day's ad revenue divided by that day's active users.
- ARPU
- Average revenue per user over a stated period, often a month.
- LTV
- Lifetime value: what an average user earns you over the whole time they keep using the app.
- DAU / MAU
- Daily and monthly active users. DAU ÷ MAU is a rough measure of how sticky an app is.
- Retention
- The share of new users still active a set number of days after install: day 1, day 7, day 30.
- Mediation
- Software that lets several ad networks compete to fill each ad request in your app.
- Waterfall
- A mediation setup that calls networks one after another in a fixed order, each with a price floor.
- In-app bidding
- A setup where networks bid at the same time in a real-time auction and the highest bid wins.
- Header bidding
- The website version of bidding: several demand partners bid before the ad server picks a winner.
- Floor price
- The lowest price you will accept for an impression. Too high and fill drops; too low and you sell cheap.
- SSP
- Supply-side platform: technology that sells publishers' ad inventory to many buyers.
- DSP
- Demand-side platform: technology advertisers use to buy impressions across many exchanges.
- Ad exchange
- The marketplace where SSPs and DSPs meet and impressions are auctioned in real time.
- ads.txt
- A public text file on a website that lists who is authorised to sell its ad space.
- app-ads.txt
- The app version of ads.txt, hosted on the developer website listed in the app store.
- Rewarded ad
- A video the user chooses to watch in return for something in the app, such as a life or coins.
- Interstitial
- A full-screen ad shown at a natural break, such as the end of a level.
- Native ad
- An ad assembled to match the look of your own content, such as a card in a feed.
- App open ad
- An ad shown while the app loads or when the user returns to it.
- Invalid traffic
- Clicks or impressions that are not from real, interested users, including bots and accidental clicks. Networks deduct it.
- Tier 1 / 2 / 3
- Shorthand for country groups by ad value. In our model Tier 1 is the US, UK, Canada and Australia.
- Seasonality
- The yearly cycle in ad prices, high in Q4 and low in January.
- Revenue share
- The cut a network keeps. Google says AdSense publishers receive 80% of revenue after the buying platform's fee, which works out at about 68% when the advertiser buys through Google Ads.