Knowledge Base & Reference
Programmatic Advertising Glossary
Every term explained twice: one plain sentence for human understanding, and one technical sentence for engineering accuracy.
CPM (Cost Per Mille)
Pricing & MetricsPlain meaning: The cost an advertiser pays for every 1,000 ad impressions served.
Technical detail: Calculated as (Total Campaign Spend ÷ Total Impressions) × 1,000. It is the universal pricing currency in programmatic ad exchanges and RTB auctions.
CPI (Cost Per Install)
Pricing & MetricsPlain meaning: The price an advertiser pays each time a user downloads and installs their app from an ad.
Technical detail: Calculated as Total Spend ÷ Number of Confirmed Installs, tracked via mobile measurement partner (MMP) postbacks with attribution matching.
CPA (Cost Per Action)
Pricing & MetricsPlain meaning: The price an advertiser pays when a user completes a specific post-install or post-click conversion event (such as a registration or purchase).
Technical detail: Calculated as Total Spend ÷ Total Attributed Actions. In programmatic systems, bidding algorithms optimize for probability of action (pAction) within defined CTA/VTA windows.
Bid Shading
Bidding & AuctionsPlain meaning: An algorithm that prevents advertisers from paying the maximum bid in first-price auctions by calculating the lowest price likely to win.
Technical detail: In first-price auctions where the highest bid pays its full face value, machine learning models estimate the clearing price distribution of the inventory to discount the submitted bid without forfeiting win probability.
Postback (Server-to-Server Callback)
Attribution & TechPlain meaning: An automated HTTP notification sent from an app attribution tool (MMP) or website back to the DSP when an install or purchase occurs.
Technical detail: An asynchronous GET/POST request containing click ID, device identifier, timestamp, and revenue payload, enabling closed-loop machine learning model retraining.
CTA (Click-Through Attribution)
Attribution & TechPlain meaning: Crediting a conversion to an ad only when the user explicitly tapped or clicked on that ad within a designated window.
Technical detail: A deterministic attribution model using a click identifier (click_id) matched to a postback within a defined lookback period (typically 7 to 30 days).
VTA (View-Through Attribution)
Attribution & TechPlain meaning: Crediting a conversion to an ad when the user saw it (an impression was rendered) without clicking, but converted shortly thereafter.
Technical detail: Probabilistic or device-graph attribution matching an impression timestamp and device identifier to a subsequent conversion event, commonly bounded by a short 24-hour lookback window.
OpenRTB
Bidding & AuctionsPlain meaning: The standardized protocol developed by the IAB that defines the communication rules between ad exchanges, publishers, and bidding platforms.
Technical detail: A standardized JSON API protocol (e.g. OpenRTB 2.5 / 3.0) transmitting device hardware, geolocation, floor pricing, and creative specs within strict sub-100ms timeout constraints.
DSP (Demand-Side Platform)
PlatformsPlain meaning: Software that allows advertisers to purchase ad impressions across multiple publisher exchanges automatically from one central dashboard.
Technical detail: A high-concurrency decisioning engine maintaining persistent exchange connections, in-memory feature caches, probabilistic scoring models, and budget pacing algorithms.
SSP (Supply-Side Platform)
PlatformsPlain meaning: Software that publishers and app developers use to sell their advertising slots to multiple buyers simultaneously.
Technical detail: A yield-optimization platform that manages publisher inventory auctions, header bidding wrappers, floor prices, and ad quality verification.
ads.txt & app-ads.txt
Quality & SafetyPlain meaning: A public text file placed on a publisher's website or app domain that lists which companies are authorized to sell their ad inventory.
Technical detail: An IAB standard (Authorized Digital Sellers) used by DSP crawlers before placing a bid to prevent domain spoofing, domain misrepresentation, and fraudulent inventory arbitrage.
sellers.json
Quality & SafetyPlain meaning: A public directory maintained by SSPs and exchanges listing every publisher and intermediary entity selling inventory through them.
Technical detail: An IAB specification providing full supply-chain transparency, allowing buyers to verify whether an inventory seller is a direct publisher or an intermediary reseller.
Invalid Traffic (IVT)
Quality & SafetyPlain meaning: Ad impressions, clicks, or events generated by non-human bots, web scrapers, or fraudulent traffic schemes rather than real users.
Technical detail: Categorized into General IVT (GIVT, e.g. known search crawlers) and Sophisticated IVT (SIVT, e.g. botnets, click farms, and hidden ad stacks), filtered out by pre-bid scoring.
Bid Floor
Bidding & AuctionsPlain meaning: The minimum price (in CPM) set by a publisher below which they will not accept any ad bids for an impression.
Technical detail: A reservation price transmitted in the OpenRTB bid request (`bidfloor`). Bids submitted below this threshold are immediately rejected by the exchange.
eCPM (Effective Cost Per Thousand)
Pricing & MetricsPlain meaning: The actual earned or spent cost per thousand impressions across any campaign regardless of whether it was bought on CPM, CPC, CPI, or CPA.
Technical detail: Formula: (Total Spend ÷ Total Impressions) × 1,000. It standardizes revenue for publishers and effective media cost for advertisers.
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