Ad Tech Glossary: RTB, Retail Media, Privacy Terms

AAMP is IAB Tech Lab's umbrella initiative, named on 26 February 2026, for making its existing advertising standards usable by AI agents: it comprises the Agentic RTB Framework and guardrails (foundations), buyer and seller agent SDKs with seven protocol components (protocols), and the Agent Registry (trust and transparency).

An ad exchange is a marketplace that runs real-time auctions for individual advertising impressions, receiving supply from publishers or SSPs and demand from DSPs, and clearing each impression to the winning bid under published auction rules.

An ad server is the system that decides which advertisement to show in a given slot, delivers the creative, and records the impression, click and other events that advertisers and publishers are billed and paid on.

"Ad tech tax" is the informal name for the total share of an advertiser's programmatic spend that is absorbed by intermediaries and waste between the advertiser and the publisher, so that the publisher receives only the remainder.

AdCP is an open protocol, launched on 15 October 2025 and governed by AgenticAdvertising.org, that defines the tasks AI agents use to discover sellers, plan and buy media, activate signals, build creative and verify brands, transported over Anthropic's Model Context Protocol or the Agent2Agent protocol.

ads.txt (Authorized Digital Sellers) is a plain-text file a publisher hosts at /ads.txt on its domain listing the advertising systems and seller account IDs authorized to sell its inventory, each marked DIRECT or RESELLER, so that buyers can reject bid requests from unauthorised sellers.

Agentic advertising is the planning, buying, selling and measurement of advertising by software agents that act on a human's brief, negotiate with other agents through a published protocol, and execute transactions on existing advertising infrastructure under human-set guardrails.

A business associate agreement is the contract HIPAA requires between a covered entity and any vendor that creates, receives, maintains or transmits protected health information on its behalf, setting out the permitted uses, the safeguards, the breach-reporting duties and the obligation to return or destroy the data.

A bid request is the OpenRTB message an exchange sends to bidders for one ad opportunity, describing the impression or impressions for sale, the site or app, the device, what is known about the user, the regulatory flags, the supply chain and the auction rules, including the time limit for a response.

A bid response is the OpenRTB message a bidder returns to an exchange for a bid request, containing zero or more bids, each with a price, a currency, the creative or its markup, the impression it applies to, the advertiser domain and, where relevant, the deal it is bidding into.

Bid shading is the practice, by a DSP or its bidding model, of bidding below the estimated value of an impression in a first-price auction so as to pay closer to the price needed to win rather than the full value.

A data clean room is a controlled environment in which two or more organizations contribute datasets that stay under their own control, a matching step joins records without revealing identifiers, and only aggregated or policy-approved outputs leave.

Closed-loop measurement is attribution in which the same organization that serves or sells the advertisement also observes the purchase, so that exposure and transaction can be joined deterministically without a third-party match.

The CLOUD Act (Clarifying Lawful Overseas Use of Data Act) is the 2018 US law that requires providers of electronic communication and remote computing services subject to US jurisdiction to preserve and disclose data in their possession, custody or control in response to lawful US process, regardless of whether the data is stored inside or outside the United States.

A commerce media network is an advertising business run by a company that holds first-party purchase, loyalty, booking or transaction data and sells advertisers access to those customers, on its own properties and on third-party media, with results attributed to the customers' subsequent purchases.

A consent string is a compact, encoded record of a user's privacy choices, generated by a consent management platform and passed through the advertising chain, that tells each vendor which purposes the user has consented to or objected to and under which legal basis.

CPNI is the information a US telecommunications carrier obtains by virtue of providing service to a customer, including the quantity, technical configuration, type, destination, location and amount of use of the service and the related billing, which federal law restricts the carrier from using or disclosing for purposes other than providing the service without the customer's approval.

Curation is the packaging of inventory from one or more sellers, often combined with audience or contextual data, into a deal ID by a party that is neither the publisher nor the advertiser, so that buyers can purchase the package through their existing DSP and the curator is paid from the clearing price.

Data residency is the requirement, or the choice, that data be stored and processed within a specified geographic or legal jurisdiction, such as a country or the European Union, usually to satisfy a law, a regulator or a contract.

Data sovereignty is the principle that data is subject to the laws and governance of the jurisdiction in which it is collected and processed, and, in practice, the ability of an organization to ensure that no foreign authority or foreign-controlled operator can access or compel access to its data outside that jurisdiction's law.

A deal ID is a unique identifier, agreed between a seller and a buyer and carried in the OpenRTB Deal object as deal.id, "a unique identifier for the direct deal," that links an impression to pre-negotiated terms such as a floor, a fixed price, an auction type and the buyers allowed to bid.

Demand path optimization is the sell-side mirror of SPO: a publisher or SSP choosing which demand sources, resellers and intermediaries to accept bids from, based on net revenue, fees taken between the advertiser and the publisher, bid quality and the cost of serving requests.

A demand-side platform is software that buys advertising impressions on behalf of advertisers by receiving bid requests from exchanges and supply-side platforms, deciding whether and how much to bid in real time, and managing budgets, targeting, creatives and reporting across many sources of supply.

A financial media network is a commerce media network run by a bank, card network, payments company, buy-now-pay-later provider or digital wallet, built on transaction data rather than on a retailer's product catalogue.

A first-price auction is an auction in which the winning bidder pays the amount it bid, signalled in OpenRTB by at: 1, as opposed to a second-price auction (at: 2, "Second Price Plus") in which the winner pays just above the second-highest bid.

A floor price is the minimum bid a seller will accept for an impression, expressed in OpenRTB as imp.bidfloor, "minimum bid for this impression expressed in CPM," with its currency in imp.bidfloorcur.

GLBA is the 1999 US federal law whose Title V requires financial institutions to tell customers how their non-public personal information is shared, to let customers opt out of sharing with non-affiliated third parties, and to maintain safeguards for that information, which constrains how a bank or payments company can use account and transaction data for advertising.

Header bidding is a technique in which a publisher offers each impression to several demand sources at the same time, before or alongside the ad server's own decision, so that the highest bid competes against direct campaigns instead of being called in a fixed sequence.

HIPAA is the 1996 US federal law whose Privacy, Security and Breach Notification Rules govern how covered entities (health plans, health-care clearinghouses and most providers) and their business associates may use and disclose protected health information, including for marketing, which requires authorization in most cases.

Incrementality is the causal effect of an advertising activity: the business outcomes, such as sales, that occurred because of the campaign and would not have occurred without it, measured against an estimated baseline.

iROAS is incremental sales divided by media cost: the revenue a campaign caused, as estimated against a baseline from an accepted incrementality method, per unit of spend.

Log-level data is the record-by-record output of an ad server, exchange or DSP, one row per bid request, impression, click or conversion, with its timestamps, identifiers, prices and decision fields, as opposed to the aggregated reports those systems present in their user interfaces.

The My Health My Data Act is Washington State's 2023 law that regulates the collection, sharing and sale of "consumer health data" by any regulated entity, not only HIPAA covered entities, requires opt-in consent for collection and sharing and a separate signed authorization for sale, bans geofencing around in-person health-care facilities, and gives consumers a private right of action.

OpenRTB is the IAB Tech Lab specification that defines the JSON (or Protocol Buffers) messages exchanged between an ad exchange and a bidder in a real-time auction: the bid request describing the impression, user, device and rules, and the bid response carrying the bid and creative.

Protected health information is individually identifiable health information, in any form, that is created or received by a HIPAA covered entity or business associate and relates to a person's past, present or future physical or mental health, the provision of health care, or payment for it.

A private marketplace is an invitation-only auction in which a seller offers inventory to selected buyers under deal terms carried in the OpenRTB Pmp object, typically with a higher floor and a first look, while still clearing each impression in real time.

Prebid Server is the open-source server-side header bidding application maintained by Prebid.org that receives an auction request from a web page, app, AMP page or CTV player, fans it out to bid adapters over OpenRTB, and returns the bids to the caller.

Programmatic guaranteed is a deal type in which a seller commits a fixed number of impressions to one buyer at a fixed price, and the transaction is executed through the programmatic pipes, with a deal ID in the bid request and an obligation on the buyer to bid on every eligible impression, rather than through a manually trafficked insertion order.

QPS, queries per second, is the number of bid requests a bidder or exchange receives or sends each second, and is the primary unit for sizing RTB infrastructure, negotiating exchange connections and measuring the waste in programmatic traffic.

A retail media network is the advertising business of a retailer that sells brands access to its shoppers on its own site, app, emails and stores, and increasingly on third-party media, using its first-party shopper data for targeting and its sales data for attribution.

ROAS is attributed sales divided by media cost: the revenue an attribution model credits to a campaign, within a stated window and on a stated basis (click or view), per unit of spend.

sellers.json is a JSON file an advertising system (SSP, exchange or reseller) hosts at /sellers.json on its domain listing the entities it sells for, so that buyers can discover whether each seller ID in a bid request's supply chain is a publisher, an intermediary or both, and who that entity is.

Supply path optimization is the practice, by a buyer or DSP, of choosing which of the many available routes to the same publisher impression to bid through, based on fees, auction rules, latency and transparency, and cutting off the others.

Server-side ad insertion is the technique of stitching advertisements into a video or audio stream on the server before delivery, so that the player receives one continuous stream rather than switching to an ad at runtime, with the consequence that ad requests, impression tracking and viewability signals may originate from the server rather than the viewer's device.

A supply-side platform is software that sells a publisher's advertising impressions by packaging each impression into a bid request, sending it to many demand sources, running or forwarding an auction, and returning the winning ad to the page, app or stream.

The SupplyChain object (schain) is an OpenRTB object carried in source.schain that lists, in order, every seller and reseller that handled a bid request before it reached the bidder, together with a flag stating whether the list is complete.

Take rate is the share of advertiser spend that an intermediary keeps as its fee, expressed as a percentage of the gross amount that passes through it; in retail media it also means the share of media revenue a platform vendor retains from a retailer's network.

The Transparency and Consent Framework is IAB Europe's standard for recording a user's GDPR and ePrivacy choices on a website or app and transmitting them, as a consent string, to every vendor in the advertising chain, together with a Global Vendor List that says which vendors participate and for which purposes.

In real-time bidding a timeout is the maximum time an exchange or header-bidding wrapper will wait for bids before closing the auction, expressed in OpenRTB as the tmax field, "maximum time in milliseconds the exchange allows for bids to be received including Internet latency to avoid timeout."

Unified ID 2.0 is an open-source identity framework that turns an email address or phone number a user has consented to share into a pseudonymous identifier for programmatic advertising, so that publishers, advertisers and platforms can match audiences across the open web, apps and CTV without third-party cookies.

Working media is the portion of an advertiser's programmatic budget that pays for the impressions actually delivered to consumers, after platform fees, data and verification fees, and waste are removed; the ANA reports it as the share of each dollar entering a DSP that reaches the publisher and the consumer.