Glossary

Ad tech terms, explained

The pricing models, ad formats, and metrics referenced across the site, defined in one place.

Ad Network: A platform that sits between advertisers who want to buy traffic and publishers who want to sell it, matching campaigns to ad zones and handling delivery, pricing, and payouts.
Ad Zone: A publisher's designated slot for serving ads — created in one of the network's supported formats, then reviewed and approved before it starts serving live traffic.
Conversion Flow: The sequence of steps a visitor takes from clicking an ad to completing the advertiser's goal — anything from a one-tap install to a multi-field signup form. Flow complexity is a major factor in choosing a pricing model.
CPA (Cost Per Action): A pricing model where the advertiser pays only when a specific action completes — an install, a lead, a signup. Highest cost per unit, lowest risk to the advertiser.
CPC (Cost Per Click): A pricing model where the advertiser pays per click, regardless of what happens after. A middle ground between CPM and CPA on both cost and risk.
CPM (Cost Per Mille): A pricing model where the advertiser pays per thousand impressions, regardless of clicks or conversions. Lowest cost per unit, most useful for testing a new offer or GEO.
CTR (Click-Through Rate): The percentage of impressions that result in a click — a core signal for how well a creative and ad format fit the traffic they're shown to.
eCPM (Effective CPM): A publisher-side metric: total ad revenue divided by total impressions, multiplied by 1,000. Used to compare earnings across ad formats and pricing models on a common basis, even when the underlying traffic was sold on CPC or CPA.
Fill Rate: The percentage of ad requests from a publisher's zone that were actually filled with an ad, rather than returning nothing.
GEO: Shorthand for the geographic location (country or region) traffic originates from — a primary targeting dimension for advertisers and a major factor in the payout rates publishers see.
Impression: One instance of an ad being displayed to a visitor, whether or not it's clicked. The basic unit CPM pricing is billed on.
In-Page Push: An ad format that renders a native-style notification directly in page content, rather than through the browser's permission-gated push system — no opt-in step required from the visitor.
Interstitial: A full-screen ad format that fires at a natural transition point — between pages, after an action, or on session start — rather than sharing the screen with other content.
Popunder: An ad format that opens a new window behind the visitor's active page, so it's seen once they finish their current session rather than interrupting it.
Social Bar: A non-intrusive on-page toolbar ad format that runs alongside a site's content without occupying dedicated ad space.