A recent antitrust trial has begun against Google's advertising technologies. This trial could have a significant impact on the company's position as the global leader in search and advertising. Following the proceedings is challenging due to the abundance of technical terms used by both parties, ranging from common concepts like header bidding, AdX, and DSP, to internal projects like Jedi Blue or Project Bernanke. To ease understanding, Digiday has compiled a glossary of terms, to which I’ve added a few of my own. These terms are likely to be frequently mentioned throughout the trial.

Ad Exchange — an online platform for automatically buying and selling ad space on websites. It operates on the principle of real-time bidding (RTB), where advertisers bid for the right to display their ads. This allows publishers to sell ad space at the highest price, while advertisers reach their target audience.

Accelerated Mobile Pages (AMP) is an open-source technology developed by Google to speed up the loading of web pages on mobile devices. It uses simplified HTML and limited JavaScript to create fast, lightweight pages. This allows publishers to develop lightning-fast pages with ads, improving user experience and potentially increasing ad revenue.

Ad server is software that allows publishers to manage ad inventory on their websites or apps. The ad server automatically selects ads to display to users and tracks interactions (impressions, clicks, etc.). It also gathers detailed analytics, performs targeting, and conducts A/B testing to maximize ad revenue.

Ad stack refers to the specific set of ad technologies and tools used to efficiently manage, measure, and monetize ad inventory. This set typically includes various components like ad servers, data management platforms (DMPs), demand-side platforms (DSPs), and supply-side platforms (SSPs).

AdTech is short for advertising technology. This umbrella term encompasses a wide range of software, platforms, and tools used in the advertising industry. AdTech includes solutions for the effective delivery of ad messages, precise audience targeting, real-time campaign optimization, and deep analysis and measurement of ad effectiveness. Essentially, these are technologies that continuously improve and transform online advertising.

Authorized buyers are participants in the advertising market who have received special permission from Google to participate in programmatic auctions on the AdX platform. These include ad agencies, DSPs, and other AdTech platforms. Authorized buyer status allows them to directly compete for ad inventory on AdX, which potentially increases competition and the effectiveness of ad campaigns.

Demand-side platform (DSP) is a system that allows advertisers to automatically purchase ad inventory and manage campaigns across multiple ad exchanges through a single interface. DSP optimizes the process of acquiring ad space, providing centralized access to various inventory and audience sources.

Display & Video 360 (DV360), previously known as DoubleClick Bid Manager, was Google’s DSP. It provided a full suite of tools for campaign planning, creative management, audience data organization, ad inventory purchasing, and performance optimization. On July 24, 2018, DV360 was rebranded and included in the Google Marketing Platform.

DoubleClick is an AdTech company founded in 1996 and acquired by Google in 2008 for $3.1 billion. It revolutionized the digital advertising industry by offering a wide range of cutting-edge ad services and technologies. DoubleClick created several key products that later became the foundation of many of Google’s modern advertising tools. This acquisition significantly strengthened Google’s position in the online advertising market.

DoubleClick DART (Dynamic Advertising, Reporting, and Targeting) was a key product of DoubleClick that revolutionized digital advertising. This tool optimized ad processes, significantly reduced the amount of unsold ad inventory for publishers, and increased their ad revenues. DART evolved with the development of technologies and the changing needs of the market, adapting to new challenges in the digital advertising industry. After Google acquired DoubleClick in 2008, DART became the basis for more advanced advertising solutions, leading to the creation of Google Ad Manager.

DoubleClick for Publishers (DFP) was Google’s platform for publishers that allowed them to manage their own ad inventory. DFP offered a wide range of tools for optimizing ad inventory, including forecasting, targeting, and reporting capabilities. This system enabled publishers to effectively monetize their content and manage both direct sales and programmatic sales. In 2018, DFP was reworked and integrated into a more powerful solution — Google Ad Manager, which further expanded the functionality of programmatic sales.

Enhanced Dynamic Allocation (EDA) was a DFP technology that automatically compared bids from various ad sources, including direct sales and programmatic. The algorithm selected the most profitable option, optimizing the publisher’s revenue and ad space fill rate.

Fillrate — the percentage of ad impressions that are filled. For example, if a site requests 100 ad impressions and only 80 are shown, the fill rate would be 80%. A high fill rate is preferred because it indicates active competition for ad space, leading to increased publisher revenue. Fill rate is a key metric in evaluating the effectiveness of a website’s monetization.

First-price auction — a type of auction where the winner pays exactly the price they bid. Such auctions are considered more transparent and easier for participants to understand, as they eliminate uncertainty regarding the final cost.

Google AdSense — Google’s ad platform. The system automatically selects relevant ads based on the content of the page and the visitors’ interests. Website owners earn revenue from clicks on ads (CPC) or from ad impressions (CPM). Unlike AdX, AdSense is primarily aimed at small publishers and bloggers, offering a more user-friendly system without requiring specialized technical knowledge.

Google Ads — Google’s advertising platform that allows advertisers to place ads in Google search results, on YouTube, in Gmail, and on millions of other websites. It offers various ad formats: text, banner, video, and mobile ads.

Google Ad Exchange (AdX) — Google’s ad exchange. Unlike AdSense, AdX is used by large publishers, providing more tools for the realization and management of ads. This allows publishers to maximize revenue by selling inventory to the highest-bidding advertisers.

Google Ad Manager (GAM) — an ad management platform that combined the features of DoubleClick for Publishers (DFP) and DoubleClick Ad Exchange (AdX). It provides publishers with tools to monetize content on websites, mobile apps, and video platforms. Ad Manager allows for the effective management of ad inventory, optimizing revenue through programmatic and direct sales, and analyzing ad campaigns.

Google Analytics (GA) is a web analytics tool that allows website owners to track and analyze visitor behavior, traffic sources, and other key metrics. GA’s close integration with other Google advertising products gives marketers the ability to optimize their strategies based on the data they collect.

Google Audience Manager is a tool that helps advertisers create and manage audiences for targeted advertising. It collects user data, segments them based on various criteria (e.g., interests or on-site actions), and enables advertisers to display more relevant ads.

Google Display Network (GDN) is Google’s advertising network, covering millions of websites, mobile apps, and video platforms. Unlike advertising within Google’s ecosystem, GDN allows for the placement of banner, text, and video ads on partner sites.

Google Marketing Platform (GMP) is a unified advertising and analytics platform that combined DoubleClick Digital Marketing and Google Analytics 360 Suite. GMP provides advertisers and agencies with tools for planning, buying, measuring, and optimizing advertising campaigns. The platform includes products such as Display & Video 360, Search Ads 360, Analytics 360, and a number of other solutions.

Google Shopping Ads (GSA) is an ad format that allows stores to display their products directly in Google search results. Unlike standard Google Ads search ads, GSA shows users images of products, their prices, and the names of the stores where they can be purchased when they search for specific products.

Header bidding — a technology that allows publishers to offer their ad inventory to multiple ad exchanges or buyers simultaneously before accessing the primary ad server. This increased competition weakened Google's preferential access, which could have led to lower ad prices and impacted its market share.

Header bidding wrapper — a container for header bidding. It manages all processes, ensuring a fast and efficient auction, which helps publishers increase revenue through intensified competition among advertisers. Essentially, it is a unified shell that coordinates all auctions in one place.

Jedi Blue — the code name of a secret deal struck in 2018 between Google and Facebook. Under this agreement, Facebook agreed to delay its plans for implementing header bidding, while Google, in turn, provided Facebook with access to its own data and other programmatic auction advantages. This deal raised serious questions about fair competition in the online advertising market. Antitrust authorities are investigating it as a potential violation of the law, as it may have limited competition and strengthened the dominant position of both companies.

Last-look — a term in the auction system when a participant sees all the bids from others and places their bid last. This gives them an advantage, allowing them to "peek" at the bids and offer just a little more to win the auction. Google's ad server previously gave its ad exchange the "last-look" advantage, which led to dissatisfaction among publishers and bolstered header bidding. However, since 2017, this advantage has officially (supposedly) ceased to exist.

Open auction transaction — a type of auction where ad impressions are available for purchase to a wide range of buyers. Unlike private auctions or direct deals, there are no restrictions on participation here, promoting maximum competition and potentially higher prices for publishers.

Open bidding — Google’s server-side header bidding technology developed in response to the widespread adoption of client-side header bidding. The introduction of Open bidding allowed Google to optimize the auction process, speed up page load times, and maintain control over ad inventory. However, this technology did not promote the growth of competition and transparency, which had become the hallmarks of traditional header bidding.

oRTB (OpenRTB) — an open standard for real-time bidding (RTB) that allows various platforms, systems, and auction participants to exchange data according to a unified protocol. This standard simplifies integration between different advertising platforms and auction participants.

Preferred deal — a direct sale using programmatic technologies where a specific buyer receives priority for the first impression, but without a guaranteed auction win.

Private auction / private marketplace — a closed type of auction where the right to purchase ad inventory is given to a limited group of buyers, pre-selected by the publisher.

Prebid — a community-managed open-source JavaScript library for implementing header bidding. Prebid significantly simplifies the integration of multiple advertising partners, allowing publishers to increase competition for their ad inventory. The library provides transparency and flexibility in auction management, potentially leading to higher publisher revenues.

Programmatic direct — a direct deal using all the benefits of programmatic technologies.

Programmatic guaranteed — a direct programmatic deal where the publisher’s ad inventory is guaranteed to be reserved for a specific buyer. This type of deal combines the advantages of traditional direct sales with the automation of programmatic buying.

Project Bernanke — a program launched by Google in 2013 to optimize the outcomes of advertising auctions on the AdX platform. It analyzed data on advertisers’ previous bids to predict effective bids for future auctions. The goal was to help Google’s clients win auctions more often by offering optimal bids. While such optimization might seem like standard practice, the problem was that Google altered the auction process itself to favor its advertisers, which likely unfairly suppressed competition. This may have reduced publisher revenues on AdX, as other platforms and advertisers did not have a similar advantage.

Project NERA — the supposed code name for Google’s plan to turn the internet into its own “walled garden”. The goal of the project was to control advertising budgets and influence auctions in favor of the company. The essence was to restrain the rise in fees that publishers charged advertisers through other platforms. Google used its data and technologies to manage ad auctions. Knowing competitors' bids, the company could influence them through the "second-price auction" mechanism, ensuring lower prices for advertisers compared to other platforms, while maintaining its own profit. This allowed Google to minimize advertisers' costs and prevent excessive growth in publisher or other ad platform fees, making its offerings more attractive.

Project Poirot — an internal Google project aimed at countering the use of header bidding technology. According to the US Department of Justice, Google used this product to analyze and identify publishers using header bidding and made adjustments to its advertising technologies to weaken their position. This could include adjusting bids or auction conditions to give an advantage to advertisers working with Google. The company sought to retain control over advertising auctions and reduce the influence of competing platforms in the ad market.

Real-time bidding (RTB) — a technology that allows advertisers to buy ad spaces on websites through real-time auctions. When a user visits a website, the system instantly conducts an auction among advertisers, and the winner gets the right to display their ad. The entire process takes fractions of a second and is repeated each time a page is visited. RTB enables advertisers to instantly assess many display parameters, ensuring its compliance with specified requirements.

Reserve price optimization — a method of managing the minimum price in ad auctions, used to increase the revenue from selling ad spaces. The reserve price is the minimum bid an advertiser must offer to display their ad. Optimizing this price allows the platform (e.g., Google) to automatically adjust bids based on advertisers' willingness to pay. Attorneys General have claimed that Google used this scheme to gain an advantage in auctions.

Second-price auction — an auction system where the participant with the highest bid wins, but pays the amount of the second-highest bid plus a minimal increment. For example, if the highest bid is $5, and the second is $4, the winner pays $4.01. The advantage of such an auction is that it encourages participants to bid based on their true valuation, as the winner only pays slightly more than the second-highest bidder, rather than their maximum bid.

Supply-Side Platform (SSP) — a platform that helps website and app owners sell ad spaces. It automates the process of selling ads through auctions, enabling publishers to maximize revenue by offering ad spaces to multiple advertisers simultaneously.

Take rate — the percentage cut that intermediaries (ad platforms) take from a transaction. For example, if an ad exchange takes 20% of the amount that advertisers spend on buying ads, its take rate is 20%.

Unified pricing — a feature that allows publishers to set uniform price floors across all ad auctions in Google Ad Manager (GAM). This tool lets publishers establish a minimum price below which ads will not be sold, regardless of the platform or demand source.

Waterfall — a process of selling ad impressions where ad codes are sequentially checked in order of priority. If the highest-priority code doesn’t purchase the impression, the system moves to the next one. The process continues until a buyer is found willing to pay the set price. This approach often results in the first platforms in the queue getting the best opportunities, while others get less favorable ones.

Yield management — a revenue optimization strategy used by publishers to maximize earnings from ad inventory. It is based on analyzing data on demand, seasonality, and other factors to set optimal prices for ad spaces. Effective yield management helps publishers strike a balance between ad space fill rates and prices, ensuring the highest possible monetization.