Part I · Chapter 1

What AdTech Is and Why It Exists

Status: reviewed

What AdTech Is and Why It Exists

The Core Idea

Digital advertising1 is paid communication by which an organization tries to influence the knowledge, attitude, or behavior of an audience in a digital environment. A company with a subscription app wants to find potential customers; the owner of another app wants to earn money from its audience; the user wants to receive content or a service and, at the same time, encounters advertising.

AdTech2 is the technology that coordinates this exchange: it helps buy and sell advertising opportunities, select a suitable ad, deliver creative3, measure events, build reporting, and carry out settlements.

The key mental model:

advertiser brings demand: budget and the intent to buy access to an audience
publisher brings supply: advertising opportunities in their media environment
AdTech coordinates selection, delivery, data, and settlements between the parties
user gets the product experience and encounters advertising

This is not one mandatory technical pipeline. A deal can be direct, pass through several platforms, or happen entirely inside a closed ecosystem. A single provider may combine several roles, and some specialized systems connect only for measurement4 or quality control.

Advertising as a Market of Coordination

The market has three basic participants.

  • Advertiser5 funds advertising for the sake of a business result (business outcome): for example, an app install, a subscription purchase, or growing awareness. It buys not a person, but the opportunity to address an audience in a specific context.
  • Publisher6 owns or operates the environment where an advertising opportunity arises: a website, a mobile app, a video service, a game. Advertising makes it possible to monetize that environment.
  • User uses a website, an app, or another media product. Their attention makes advertising meaningful, but the user is not inventory7, usually does not sell advertising, and does not pay for media.

Using two mobile apps as an example:

Participant What it contributes What it wants to get Main constraint
An app with a paid subscription — advertiser Budget, goal, creative Attract users who will take out a subscription Not spending budget on unsuitable opportunities
A content or gaming app — publisher Media environment and advertising opportunities Earn revenue8 without ruining the user experience Balancing monetization, quality, and ad load
A person — user Attention, context of use, and a possible reaction Content or app functionality on acceptable terms Relevance, privacy, safety, and not being overloaded with ads

The value exchange is not symmetric. The advertiser pays for media access; the publisher receives advertising revenue; the user gets the product and the advertising experience, but at the same time bears a cost in the form of time, attention, and possible use of their data. That is why effectiveness for the advertiser, revenue for the publisher, and quality of experience for the user can conflict. A significant part of AdTech exists precisely to manage these conflicting goals at scale.

Supply, Demand, and Advertising Inventory

Demand9 is the budgets and intent of advertisers to buy suitable advertising opportunities. Around it sits the buy side or demand side: people and systems that help plan and buy media.

Supply10 is the advertising opportunities available from publishers. Around it sits the sell side or supply side: people and systems that help describe, sell, and deliver advertising.

These words denote sides of the market, not specific technologies. A DSP (Demand-Side Platform)11 belongs to the demand side not because it “creates demand,” but because it acts in the buyer’s interest. An SSP (Supply-Side Platform)12 belongs to the supply side because it helps publishers manage the sale of opportunities.

The subject of the deal is advertising inventory: the set of available or projected opportunities to show an ad. Inventory is bounded by the environment, the placement, the format, the timing, the publisher’s rules, and the acceptable audience context. It is not a list of users, and it does not mean that future impressions already exist in a warehouse. Supply and inventory are not synonyms: supply is a side of the market (who sells, and why), inventory is the subject of the deal (what exactly is sold); inventory without a seller is not yet supply.

It is useful to distinguish three levels:

  1. Placement13 or ad slot — a pre-defined location or rule for when advertising appears: for example, a full-screen block after a level is completed in a game.
  2. Ad opportunity14 — a concrete opportunity to select and show an ad that arises when the user reaches that location.
  3. Impression15 — a delivery or display event of the selected ad, registered by a system according to a specific rule.
placement exists in the app's design
    ↓ user completed a level
an ad opportunity arises
    ↓ the system selected a creative
the ad is delivered; an impression is registered according to the system's rule

Even that last statement requires care. Served16, rendered17, and viewable impression18 are different states: sending an ad does not prove that it rendered and actually entered the person’s field of view. Precise definitions and metrics will appear in chapter 3.

From a Market Problem to Technology

Without technology, an advertiser would have to negotiate separately with every publisher, manually transfer materials, agree on formats, and reconcile incompatible reports. A publisher would have to find buyers for a huge number of short-lived opportunities. In a digital environment, a single opportunity can appear and disappear faster than a human can make a decision.

AdTech appears where the market requires repeatable technical execution:

Market problem Required function Typical solution categories
Many advertisers and publishers Aggregation: pool demand or supply DSP, ad network19, SSP
Each opportunity needs a suitable buyer and creative Matching and decisioning DSP, ad network, ad server20, publisher stack
There is often little time left to make a decision Automated execution Buying/selling platforms, exchange21
The creative must reach the right environment and format Ad serving and interoperability Ad server, SDK, platform integrations
Parties see events from different vantage points Measurement and reporting Ad server, measurement providers; in mobile — MMP (Mobile Measurement Partner)22
A delivery may be unsuitable or low-quality Verification23 and risk controls: verification is an independent assessment of display conditions, fraud detection is a separate function that identifies invalid traffic (chapters 36–37) Verification provider, fraud detection and quality-control systems
Participants need to reconcile volumes and payments Reconciliation and settlements Reporting, billing, and finance systems

Standards and shared protocols reduce the number of pairwise integrations: it becomes easier for the parties to describe inventory consistently, pass decisions along, and understand the chain of sellers; for example, ads.txt shows a buyer who is authorized to sell a given publisher’s inventory, and sellers.json shows who actually stands behind each seller and intermediary in the chain (chapter 38). One example is RTB (real-time bidding)24, where an individual opportunity can be auctioned in real time. But RTB is only one mechanism inside programmatic25, i.e. automated buying and selling; and programmatic is only part of AdTech. Direct deals, reserved buying, and closed platform ecosystems also use AdTech.

Why Intermediaries Exist

Intermediary26 is a participant that connects the sides of the market or performs a specialized function. Intermediaries arise not from a need to add more companies to the chain, but from the division of labor:

  • an agency27 manages media buying on behalf of the advertiser;
  • a demand-side provider aggregates access to supply and performs selection for the advertiser;
  • a sell-side provider aggregates buyers and helps the publisher sell inventory;
  • a connective layer passes opportunities and decisions between the parties;
  • an ad server manages the selection and delivery of creative;
  • measurement and verification providers provide an independent point of observation;
  • data providers28 supply permitted signals, while identity providers29 link identifiers across systems.

An intermediary is justified when the value from reach30, aggregation, interoperability, speed, measurement, or risk control exceeds its cost and complexity. But not every intermediary is needed in every deal. The short path is not always better functionally, and the long one is not always more effective. What needs to be evaluated is the function performed, its cost, its transparency, and its conflicts of interest.

One publisher, two ways to sell. A gaming app sells its full-screen block after a level directly to an agreed advertiser: the path is short, with no intermediary fees, but with its own integration, its own reporting, and reach limited to the buyers the publisher has managed to strike deals with. It opens the remaining opportunities in the same block to many buyers through an SSP: the path is longer and the platform keeps a fee, but the publisher gains demand aggregation, automated execution, and the filling of opportunities that would otherwise go unsold. Both paths work at the same time, and for every hop the question is the same: what function did it perform, and did that function justify its cost?

A Map of the Advertising Ecosystem

The following diagram shows logical roles and possible paths, not a universal order of HTTP calls:

BUYING SIDE                    CONNECTIVE LAYER              PUBLISHER SIDE

Advertiser
   ├─ [Agency], [Advertiser ad server] — can support any buying path
   ├─ [Direct buying] ───────────────────────────────────────────────┐
   ├─ [Ad network] ─────────────────────────────────────────────────┤
   └─ [DSP] ⇄ [Ad exchange / connective layer] ⇄ [SSP] ─────────────┤
                                                                    ├→ [Publisher ad server] → Publisher → User
                                                                    └→ Publisher → User (path without a publisher ad server)

Cross-cutting functions connected to several participants:
[Measurement providers]
[Verification]   [Data / identity providers]

The branches show possible paths that can be combined; the square brackets denote logical roles, not necessarily separate companies. In reality:

  • one company may combine DSP, ad network, exchange, SSP, or ad server;
  • an SSP and a publisher ad server may participate in the same flow: the SSP provides access to programmatic demand, while the publisher ad server matches that and other sources and manages delivery; paths also exist without one of these links;
  • direct buying can bypass part of the connective layer;
  • a closed platform can hide several roles behind a single API and a single commercial contract;
  • measurement, verification, and identity usually work across the chain, not “between” two mandatory neighbors.

For now, the categories on the map are only needed as navigation:

Category Where it sits One core function
Agency Advertiser side (buy side) Plans and executes media buying for the advertiser
DSP Advertiser side (buy side) Automates buying opportunities from several supply sources
Ad network Between buyers and publishers Aggregates and packages supply/demand as a manageable offering
Ad exchange Connective layer Connects buyers and sellers for an automated deal
SSP Publisher side (sell side) Helps the publisher manage buyer access to inventory
Ad server Advertiser or publisher side Selects, delivers, and registers advertising according to defined rules
Measurement provider; a specialized mobile category — MMP Across the chain Measures advertising events and outcomes; an MMP specializes in mobile acquisition and attribution31
Verification provider Across the chain Independently evaluates the quality and conditions of display
Data / identity provider Across the chain Supplies or connects permitted data signals for activation32 and measurement

Full definitions, varieties, and combinations of these roles are the topic of chapter 2.

The Three Flows of a Single Advertising Deal

The main mistake when reading the ecosystem map is to imagine that creative, data, and money move along a single arrow. Let’s look at one ad for a subscription app inside a publisher’s content app.

1. The Display and Delivery Flow

user opens a screen in the publisher app
    → the publisher creates an ad opportunity
    → available systems select an ad
    → the selected creative, or an instruction to load it, is returned to the app
    → the app loads and renders the creative
    → the user may notice the ad and interact with it

In a typical flow, the process starts on the publisher’s side, because that is where the opportunity arises. The decision may come from a direct campaign33, an ad network, a DSP/SSP path, or a closed platform. The creative, meanwhile, may be delivered not by the same service that made the commercial decision: an ad server or a CDN often participates in delivery separately.

2. The Data Flow

advertiser side:
goal + campaign rules + creative metadata
                         ↓
publisher context → selection systems → selected ad + delivery metadata
                         ↓
impression / click / outcome events → measurement + reporting → optimization

Campaign is an organized set of advertising activity with a goal, a budget, and creatives. Before delivery, the advertiser side tells the systems the conditions of that activity. When an opportunity arises, the publisher side may pass a description of the app or site, the placement, the format, the time, and — as permitted by platform rules — signals about context, device, or audience. The selection systems match supply with demand and return a result.

The systems link objects and events with identifiers such as request_id, campaign_id, and creative_id; the specific fields and rules depend on the integration. After delivery, different participants may separately register an impression and a click34. If the user installs the advertised app and takes out a subscription, the outcome event may reach measurement systems — provided the right integrations exist and within platform/privacy restrictions.

This reverse flow is usually asynchronous and does not have to travel the same network path as the ad request. The advertiser, the publisher, and intermediaries may have different points of observation, timestamps, and counting rules, so their reports do not have to match perfectly.

3. The Money Flow

Advertiser media spend
    → buying channel / media seller or sellers
    → publisher revenue

Separately, depending on contracts:
advertiser or publisher → service / SaaS fee → technology provider

Media spend35 is the money an advertiser allocates to buying advertising. A portion passes to media sellers and ultimately forms publisher revenue36; along the way, fees may be deducted. But not every provider takes a share of every advertising payment. An agency often receives a percentage of media spend, sometimes a fixed fee37; an ad server, an MMP, a verification or data provider may receive a separate service fee, SaaS fee, or other contractual payment. Some participants only pass along or measure events and never touch media money at all.

Therefore, the three sums must not be treated as synonyms:

  • advertiser spend — the buyer’s cost;
  • intermediary fee — payment for a specific intermediary or technology function;
  • publisher revenue — the revenue of the inventory seller.

Exact pricing models, margins, and the path of a hypothetical $100 are covered in chapter 4. What matters here is the direction: advertising and data move in both directions, while money mostly flows from the advertiser to the owners of supply and to service providers.

The Advertising Lifecycle: Not a Line, but a Feedback Loop

Advertising work begins before the first impression and does not end with a render:

business goal
  → planning and setup
  → preparing campaigns and creatives
  → access to media and ad selection
  → delivery and render
  → user reaction and business result
  → measurement and reporting
  → optimization, reconciliation, and settlements
  ↺ next planning iteration

Let’s walk through the cycle for a subscription app.

  1. Business goal. The advertiser decides to acquire users who take out a subscription with acceptable economics.
  2. Planning and setup. It defines the audience, the available channels, the budget, and the method of measurement. This is where demand is formed.
  3. Preparation. A campaign and several creatives are created. The systems receive delivery rules and the necessary integrations.
  4. Access to media and ad selection. The publisher provides opportunities directly or through sell-side systems. Buying systems find suitable opportunities and select a creative. The specifics of bidding, targeting38, and pacing39 will appear in later chapters.
  5. Delivery and render. The creative is delivered to the publisher app and rendered; events corresponding to the participants’ points of observation are registered.
  6. Reaction and result. The user may ignore the ad, click it, install the app, and later buy a subscription. The presence of an event does not prove the ad’s causal impact.
  7. Measurement and reporting. The systems aggregate the observed impressions, clicks, and outcomes. Attribution and mobile measurement require separate mechanisms and will be covered later.
  8. Optimization and settlements. The advertiser redistributes future demand based on the available signals; the publisher adjusts its monetization strategy; the participants reconcile reports and carry out settlements.

The feedback loop is the reason AdTech is not just delivery infrastructure. Value arises when observations about the past change future decisions, but the quality of those decisions is limited by data completeness, measurement correctness, and the participants’ misaligned incentives.

AdTech and MarTech: A Working Boundary

MarTech40 is technology for the broader management of marketing and the customer lifecycle: customer data, communications, and the advertiser’s owned channels. The boundary is not standardized, so it is more useful to classify a system by its primary job than by the label on the vendor’s website.

Question AdTech MarTech
Primary object Paid media and advertising opportunities Customer relationships and marketing operations
Main coordination Between the buying side and the selling side Inside the advertiser and its owned channels
Typical channels Publisher sites and apps, ad platforms, media marketplaces Email, CRM, push, the brand’s own site or app, customer journeys
Typical systems DSP, SSP, ad network, exchange, ad server CRM, marketing automation, CDP41, email/push platforms
Primary result Buy, sell, select, deliver, and measure advertising Manage customer data and communications across the lifecycle

The overlap is large. Measurement, attribution, identity, CDP, and activation can serve paid media and owned channels at the same time. For example, a subscription-purchase event lives in product/backend systems, may enter a MarTech retention process, and at the same time become an outcome signal for AdTech measurement. That is why AdTech vs MarTech is a working rule of thumb, not an impermeable boundary.

Common Confusions

  • “The user is the inventory.” No. Inventory is advertising opportunities in a media environment. The user creates context and attention but remains a separate participant with their own interests and rights.
  • “An impression means the person saw the ad.” Not necessarily. Served, rendered, and viewable describe different points of the process, and viewability by itself does not prove human attention.
  • “Every intermediary resells media and keeps a share of the spend.” No. Some receive a separate service/SaaS fee, and some take no part in the media money flow at all.
  • “The more intermediaries, the worse.” Additional hops add fees, latency, and the risk of opacity, but they can also provide reach, aggregation, interoperability, measurement, and quality controls. The question is what function each hop performs and what it costs.
  • “AdTech = programmatic = RTB.” No. RTB is one mechanism of programmatic; programmatic is part of AdTech; AdTech also supports direct and closed-platform advertising.
  • “AdTech and MarTech are strictly separated.” No. AdTech primarily coordinates paid media, while MarTech handles the customer lifecycle and owned channels, but data, identity, measurement, and activation often overlap.

What to Remember

  1. Digital advertising is a market of coordination between advertiser, publisher, and user, not just the delivery of a banner.
  2. The advertiser creates demand, the publisher creates supply; the sides of the market must not be confused with platform names.
  3. Advertising inventory is available or projected opportunities, not users and not pre-manufactured impressions.
  4. Placement, ad opportunity, and impression are different stages: a placement rule, an arisen opportunity, and a registered event.
  5. AdTech exists because of scale, fragmentation, the speed of selection, delivery, interoperability, measurement, and settlements.
  6. Intermediaries perform functions; no category is required to be present in every deal.
  7. The display flow, the data flow, and the money flow differ in direction, participants, and timing.
  8. The advertising lifecycle forms a feedback loop: measurement of past events influences future decisions and spending.

Check Yourself

  1. Why is the user a participant in the advertising market but not advertising inventory?
  2. How does a placement differ from an ad opportunity and an impression?
  3. For the advertising of a subscription app, draw the creative flow, the event flow, and the money flow separately. Which arrows will not coincide?
  4. What intermediary function can justify an additional hop, and in which case would that hop turn out to be superfluous?

Sources and Further Reading

  1. IAB Tech Lab — OpenRTB
  2. IAB Tech Lab — Supply Chain & Foundations
  3. IAB Tech Lab — sellers.json and SupplyChain Object
  4. IAB Tech Lab — About ads.txt
  5. Competition and Markets Authority — Intermediation in open display advertising
  6. IAB UK — Demand Side Platform (DSP)

Footnotes

  1. Digital advertising — paid communication by which an advertiser tries to influence the audience’s knowledge, attitude, or action in a digital environment. It is a market of coordination between advertisers (demand), publishers (supply), and users, not just banner delivery: the parties’ values and goals conflict, and a significant part of AdTech exists to manage those conflicts. ↩

  2. AdTech (advertising technology) — the set of technologies that coordinate the buying, selling, selection, delivery, measurement, and payment for advertising between advertisers, publishers, and intermediaries: from the ad server and DSP/SSP to measurement and verification systems. Programmatic is only part of AdTech: direct deals, reserved buying, and closed platforms also run on AdTech. The boundary with MarTech is drawn by primary purpose: AdTech coordinates paid media, MarTech the customer lifecycle. ↩

  3. Creative — the advertising material that is delivered and shown to the user: a banner, a video, a native format, a playable. Along with targeting rules it is an object of delivery and must match the format and rules of the publisher’s environment; for a campaign, several creatives are usually prepared. ↩

  4. Measurement — the function of recording and aggregating advertising events (impressions, clicks, outcomes) for reporting and optimization. Measurement providers give an independent point of observation; different participants have different timestamps and counting rules, so reports do not have to match perfectly. In mobile, the dedicated category is the MMP. ↩

  5. Advertiser — a market participant that funds advertising for a business result: installs, subscription purchases, growth in awareness. It buys not a person but the opportunity to address an audience in a specific context; it creates demand and sets goals, budget, and creative. ↩

  6. Publisher — the owner or operator of a media environment where advertising opportunities arise: a website, a mobile app, a video service, a game. It monetizes the environment with advertising, creates supply, and decides which placements, formats, and buyers to admit, balancing revenue against user experience. ↩

  7. Advertising inventory — the set of available or forecast opportunities to show advertising, bounded by the environment, the slot, the format, the time, the publisher’s rules, and the permissible audience context. Inventory is not a list of users and not a warehouse of pre-produced impressions: an opportunity arises and disappears at the moment the product is used. ↩

  8. Revenue — the amount recognized by the chosen entity under its accounting rules on its ledger boundary. Estimated dashboard value, invoiced amount, settled amount, and recognized revenue can be different states of one chain; for comparison, the period, timezone, currency conversion, taxes/refunds, and participant must be agreed. How much of the money passing through a platform it recognizes as revenue depends on its principal or agent role (gross/net presentation), not on the size of the invoice. ↩

  9. Demand — the budgets and intent of advertisers to buy suitable advertising opportunities; the market side around which the buy side / demand side groups — the people and systems that help plan and buy media (agencies, DSPs). Demand is a market side, not a specific technology: platforms must not be confused with sides. ↩

  10. Supply — the advertising opportunities available from publishers; the market side around which the sell side / supply side groups — the people and systems that help describe, sell, and deliver advertising (SSPs, publisher ad servers). Supply is the set of inventory for sale, not the name of a platform. An ad network aggregates both supply and demand, so it sits between the sides rather than inside one of them. ↩

  11. DSP (Demand-Side Platform) — a platform that automates the purchase of advertising opportunities for an advertiser: it aggregates access to several supply sources, evaluates each opportunity, and decides whether to bid and how much to pay. It belongs to the demand side not because it “creates demand” but because it acts in the buyer’s interest. ↩

  12. SSP (Supply-Side Platform) — a platform that helps publishers manage the sale of inventory: it sets buyer access rules, connects programmatic demand (DSPs, exchanges), and runs or forwards the auction. SSP and exchange functions are often combined in a single product. ↩

  13. Placement (ad slot or selectable media scope) — an overloaded product term. On the publisher side, it is a predefined ad slot or rule for ad appearance that generates ad opportunities as the product is used. On the buy side, placement can mean an explicitly selected delivery environment — a site, app, channel, video, section, or individual slot. The entity level must be clarified from the product contract. ↩

  14. Ad opportunity — a specific opportunity to select and show an ad that arises when a user reaches a placement. A short-lived event: in a digital environment it can vanish faster than a person can make a decision, so systems process it in milliseconds, and in programmatic it is put up for bidding as a separate unit. ↩

  15. Impression — a delivery or display event for the selected ad, recorded by a system under a specific rule; a counting unit, not a fact of human perception. Served, rendered, and viewable are different delivery states, so the counters of different participants in the same deal may not match. ↩

  16. Served impression — an impression counted on the fact that the ad server or selling platform returned the creative (or a reference to it) in response to a request; it proves sending, but not loading, rendering, or visibility. The earliest and largest number in the served → rendered → viewable ladder. ↩

  17. Rendered impression — an impression counted after the creative has loaded and been rendered on the user’s device (usually on a signal from client-side code: a pixel or an SDK event after render). It proves rendering, but not that the creative entered the visible area of the screen or was noticed; the MRC standard for display counts an impression precisely on client-side load/render. ↩

  18. Viewable impression — an impression that met the applicable geometry/time criteria of viewability (the classic MRC benchmark: at least 50% of the creative’s pixels on screen for one continuous second for display and two for video). Viewable means a standardized opportunity to see, not a person’s attention; non-viewable (the measurement took place, the criteria were not met) is not the same as non-measurable (the status could not be determined). ↩

  19. Ad network — an intermediary that aggregates advertising opportunities (inventory) from many publishers and sells them to advertisers as a single packaged product: the network takes over supply selection, pricing, and delivery, while the buyer gets one manageable offering instead of a dozen separate contracts. Prices inside the network are usually opaque to the buyer. Historically, many ad networks added auction mechanics and rebuilt themselves as ad exchanges, so both functions are often combined under one brand. ↩

  20. Ad server — a system that selects, delivers, and logs advertising under given rules. There are publisher-side ad servers (matching direct campaigns, networks, and programmatic demand, managing delivery) and advertiser-side ones (storing creatives, counting impressions and clicks); the term denotes a function, not a market side. ↩

  21. Ad exchange — the transaction layer that connects buyers and sellers in an automated deal, usually through a real-time auction (RTB). The difference from an ad network is transparency: the buyer sees the description of an individual opportunity and decides for themselves how much to pay for it, and the price is set by the auction rather than by the network’s price list. An exchange is not necessarily a separate company between the DSP and SSP: exchange and SSP functions are often combined in a single product. ↩

  22. MMP (Mobile Measurement Partner) — a specialized category of measurement providers for mobile: it measures installs and in-app events, performs attribution, and provides independent data to the parties in the deal. Not a synonym for just any measurement system. ↩

  23. Verification — an independent assessment of the quality and conditions of delivery: viewability, environment, fraud, compliance with the rules. Verification providers plug in across the chain and take no part in the commercial decision about the deal. ↩

  24. RTB (real-time bidding) — a programmatic buying mechanism in which an individual advertising opportunity (opportunity) is put up for an automated auction and sold in a fraction of a second — before the page or app has even shown the ad. Buyers submit bids, usually through a DSP; trading happens on an ad exchange or inside an SSP with an auction function. RTB is not a synonym for programmatic, let alone AdTech: it is one of the automated buying mechanisms within the broader stack. ↩

  25. Programmatic — automated buying and selling of advertising: decisions about each opportunity are made by systems, not people. RTB is only one of its mechanisms; programmatic also includes automated reserved and direct mechanics without an auction. Programmatic is part of AdTech, but not all of AdTech. ↩

  26. Intermediary — a participant that connects market sides or performs a specialized function: agencies, DSPs, ad networks, exchanges, SSPs, ad servers, measurement, verification, and data providers. It is justified when the value of its function (reach, aggregation, interoperability, speed, measurement, risk control) exceeds the cost and complexity; it need not be present in every deal and does not necessarily retain a share of the media money — some intermediaries receive a separate service or SaaS fee. ↩

  27. Agency — a contractor company that plans and executes marketing and media work on behalf of an advertiser: develops strategy, prepares creative, selects channels, launches a campaign, and reports on results. An advertiser can keep media buying in-house, hand it to an agency in full, or split the responsibility. An agency is an organization and a contractual role, as opposed to a media buyer — an operational function that can also work inside an advertiser. ↩

  28. Data provider — a provider that sells or supplies datasets, attributes, or ready-made audience segments for targeting, measurement, and enrichment. It works in parallel to the buying chain, not “between” two mandatory neighbors; third-party segments are usually paid for by the buyer — often as a data CPM charged through the buying platform on top of the media cost. Not to be confused with an identity provider, which does not supply data but establishes correspondence between identifiers. ↩

  29. Identity provider — a provider that links or translates identifiers from permitted sources for activation, measurement, and related use cases: for example, matching an advertiser’s customer ID with a platform-specific ID. It does not create consent and does not prove the identity of a real person: matching within one solution is not legal permission. It differs from a data provider in its task — it does not supply datasets but establishes correspondence between identifiers. ↩

  30. Reach — the de-duplicated number of unique entities (persons, devices, households, accounts, or a modeled audience) that received at least one qualifying exposure in a period, or the share of such entities in an explicitly defined population: reach rate = reached unique entities / declared universe × 100%. Comparable only with identical entity definition, exposure rule, population, de-duplication scope, and period. ↩

  31. Attribution — the rules by which the available advertising touchpoints (impression, click) are matched to outcomes (install, registration, purchase) and receive credit for the conversion. Attribution answers the question “which source was credited with the action under the chosen rules,” not “whether the ad was the true cause”: credit does not prove causality. Attribution providers are a separate cross-cutting category; in mobile, the MMP. ↩

  32. Activation — handing data or an audience segment to a system that can use it for targeting, suppression, personalization, or measurement: from a CDP/DMP to a DSP, from the advertiser’s CRM to a walled garden, from an identity graph to an SSP. Before activation, data is a record in storage; after it, a rule that affects real impressions. Activation requires matching identifiers between the source and the receiving platform and a permitted legal basis. ↩

  33. Campaign — an organized set of an advertiser’s advertising activity with a goal, a budget, delivery rules, and creatives. Before delivery, its conditions are communicated to the buying systems; objects and events are linked by identifiers such as campaign_id. ↩

  34. Click — a qualifying user-initiated interaction with an ad, recorded under a specific system’s rule. Even a single action has several measurement points: initiated, measured (click tracker), received (destination), and resolved (landing page) clicks need not match due to dropped connections, redirect chains, and filters. ↩

  35. Media spend — the money an advertiser allocates and spends on buying advertising. It passes through the media sellers and ultimately forms publisher revenue, shrinking along the way by fees; it is not a synonym for publisher revenue, nor for intermediary fees — these are different amounts in one chain. ↩

  36. Publisher revenue — the amount the publisher recognizes as revenue under its own accounting rules from media payments for its inventory; in the simple case it equals the publisher payout, but recognition (accrued / billed / settled) follows the publisher’s policy, not the moment of payment. It differs from advertiser spend by the sum of all fees in the chain; participants’ service and SaaS fees outside the media money do not count toward it. ↩

  37. Fixed fee — an amount agreed in advance for a period, a scope, or a deliverable that does not depend on the volume of media transactions: an agency retainer, a setup or managed-service fee, a minimum monthly commitment, a flat sponsorship fee. It is usually a flow separate from media money: it is not deducted from the media dollar and does not become a publisher payout or a take rate — unless a specific contract bundles software and media charges into one invoice. It is chosen for predictability and to remove the “fee grows with spend” conflict; the provider bears the risk that the agreed scope will require more work. ↩

  38. Targeting — the campaign’s rules about to whom and where an ad may be shown: hard controls (eligibility rules — geo, device, context, audience/keyword criteria, exclusions) that restrict the set of permitted opportunities, and signals/hints that in algorithmic products only steer delivery without narrowing the eligible set. Targeting answers the question “for which opportunities/users/contexts is showing possible,” as opposed to placement (“where exactly”) and optimization (“which of the permitted impressions to choose”); even if the API stores them in one object, these are different axes. ↩

  39. Pacing — the policy of distributing spend over time within budget constraints: whether to spend evenly, accelerate on cheap or high-quality opportunities, or hold back the budget. Pacing allocates the resource but does not promise even spending: the available opportunities and the allocation change. ↩

  40. MarTech (marketing technology) — technologies for the broader management of marketing and the customer lifecycle: customer data, communications, and the advertiser’s own channels (CRM, marketing automation, CDP, email/push platforms). It overlaps with AdTech in measurement, attribution, identity, and activation, so the boundary is drawn by the system’s primary purpose, not by the vendor’s label. ↩

  41. CDP (Customer Data Platform) — a system that collects first-party events and customer data from the product, CRM, and other systems into a persistent unified customer record and makes profiles, events, and segments available to downstream systems. It does not buy media and does not assign attribution credit; it belongs to customer lifecycle management, which makes it part of MarTech. ↩