AdTech Wiki

Protocols & Standards

Industry specifications that let buyers, sellers and verifiers interoperate.

• OpenRTB

  OpenRTB is the IAB Tech Lab specification that standardizes how an exchange or SSP sends a bid request describing an impression to DSPs and how DSPs answer with a bid response, so thousands of buyers and sellers can trade in real time through one common JSON message format.

• ads.txt & app-ads.txt

  ads.txt (for websites) and app-ads.txt (for apps and CTV) are public text files hosted by a publisher that list every ad system and account ID authorized to sell its inventory, letting buyers reject unauthorized resellers and domain spoofing.

• sellers.json & SupplyChain Object

  sellers.json is a file published by an SSP or exchange that discloses the identity of each seller account it represents, while the SupplyChain object in the bid request records every hop the impression passed through; together with ads.txt they let buyers verify the full path from publisher to DSP.

• VAST

  VAST is the IAB Tech Lab XML schema that tells a video player which ad creative to play, where its media files are and which tracking URLs to fire, making video and CTV ads portable across players and ad servers.

• TCF & GPP

  IAB Europe's TCF and IAB Tech Lab's GPP are frameworks that encode a user's privacy choices into a standardized string passed through the ad chain, so every vendor can tell whether it has a legal basis to process data in that jurisdiction.

• VAST Tag & Wrapper Chains

  A VAST tag is the URL a video player calls to fetch an XML ad response. The response is either Inline (it holds the media files and tracking URLs) or a Wrapper that points to another ad server's VAST, so one impression can pass through several redirects before a playable creative arrives.

• SKAdNetwork & AdAttributionKit

  SKAdNetwork (SKAN), now extended by AdAttributionKit, is Apple's privacy-preserving attribution framework that reports app installs and coarse post-install conversion values to ad networks without revealing user-level identifiers, using delayed and anonymised postbacks.

Architecture & Mechanisms

How auctions, identity and traffic quality actually work under the hood.

• Header Bidding

  Header bidding is a technique where a publisher offers each impression to multiple SSPs and exchanges simultaneously before calling its ad server, so demand competes on price at once instead of in a sequential waterfall.

• Supply Path Optimization (SPO)

  Supply path optimization is the practice of buyers choosing the fewest, cheapest and most transparent routes to the same publisher inventory, cutting redundant resellers so more of the media budget reaches the publisher.

• Invalid Traffic (IVT)

  Invalid traffic is any ad impression or click that does not come from a real, interested human, ranging from known data-center crawlers (GIVT) to sophisticated fraud such as bot farms, app spoofing and ad stacking (SIVT).

• Identity Resolution

  Identity resolution links signals such as hashed emails, device IDs and contextual data into a persistent identifier so advertisers can target, cap frequency and measure without relying on third-party cookies.

• Bid Shading

  Bid shading is a DSP algorithm that lowers a bid below the buyer's maximum value in first-price auctions, estimating the lowest price likely to still win so advertisers do not overpay.

• Mobile Ad SDK

  A mobile ad SDK is a software library that app developers embed to request, render and track ads (banner, interstitial, rewarded video, native) inside an app, handling device signals, consent and creative display that a web page would otherwise handle through tags.

• Mobile Measurement Partner (MMP)

  A Mobile Measurement Partner (MMP), such as Adjust, AppsFlyer, Singular or Kochava, is an independent attribution platform that tells app marketers which ad network, campaign and creative drove each install and in-app event, giving one neutral source of truth across many media sources.

• Ad Server

  An ad server is the system that decides which ad to show for an impression and records delivery. Publisher ad servers manage direct deals and programmatic demand on owned inventory; advertiser ad servers host creatives, rotate them and count impressions and clicks across all media bought.

Formats & Channels

Media environments and emerging programmatic channels.

• Connected TV (CTV) & SSAI

  Connected TV advertising delivers video ads to streaming content on internet-connected televisions; server-side ad insertion (SSAI) stitches ads directly into the content stream so playback is seamless and ad blockers cannot separate them.

• Retail Media Networks (RMN)

  A retail media network is an advertising business run by a retailer or commerce platform that sells ads on its own sites, apps and stores, and off-site across the open web, using first-party shopper and purchase data for targeting and closed-loop sales measurement.

• Data Clean Room

  A data clean room is a secure environment where two or more parties, such as a retailer and an advertiser, match and analyze their first-party data under strict privacy controls, getting aggregated insights without exposing raw user-level records to each other.

Business Models & Metrics

Pricing, fees and the numbers that decide who earns what.

• CPM, eCPM & vCPM

  CPM is the price paid per 1,000 ad impressions; eCPM normalizes revenue from any pricing model into a per-1,000-impression figure so different demand sources can be compared; vCPM counts only viewable impressions.

• Take Rate

  Take rate is the percentage of advertiser spend that an ad tech intermediary keeps as its fee; in programmatic chains, several DSP and SSP take rates stack, so only part of the original budget reaches the publisher.

• Deductions & Reconciliation

  Reconciliation is the month-end process where ad partners compare impression and revenue counts and agree what will be paid; deductions are amounts removed for discrepancies, invalid traffic or brand-safety violations, often months after delivery.

• Owned & Operated (O&O) Inventory

  Owned & Operated (O&O) inventory is ad space a company sells on properties it owns itself, such as its own apps, sites or streaming channels, as opposed to extended or third-party supply it resells through a network or exchange on behalf of other publishers.

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