Behind-The-Scenes of Header Bidding and How It Creates Better Ad Quality for Publishers

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Mastering header bidding is essential for maximizing ad revenue, improving user experience, and fostering competitive, real-time auctions between multiple demand sources.

Header bidding has revolutionized programmatic advertising by allowing multiple demand sources to bid on ad inventory simultaneously, rather than sequentially as in traditional waterfall auctions. This competition results in higher CPMs, better ad quality, and greater control for publishers. 

Today, header bidding is an essential strategy for maximizing revenue and improving the user experience. 

In addition, the auction enables publishers to present their ad inventory to several SSPs, ad networks, and exchanges simultaneously before involving the ad server. This creates a more competitive and transparent auction, as demand sources bid in real-time for the same inventory.

But let’s dive headfirst into this bidding auction. All puns intended. 

How Header Bidding Works

Header bidding enables multiple advertisers to bid on a single ad impression simultaneously. This process begins when a user loads a webpage, triggering the header bidding script to send ad requests to various demand sources like Supply-Side Platforms (SSPs), Ad Exchanges, and Demand-Side Platforms (DSPs). Each demand source responds with a bid and ad creative in real-time, after which the highest bid is selected and displayed to the user.

The real-time bidding (RTB) process enables advertisers to bid on ad impressions within milliseconds, helping publishers secure the best price for their inventory while allowing advertisers to reach their target audiences effectively.

Behind-the-Scenes Mechanics

Header bidding operates on a system that involves creating HTTP requests, handling bid responses, and leveraging user data for efficient targeting.

HTTP Request Generation and Processing

When a user visits a webpage, the header bidding script sends HTTP requests to demand sources. These requests, typically formatted in JSON or XML, contain parameters such as ad unit size, placement ID, and user data. Demand sources process these requests and return bid responses with a bid amount and ad creative.

Pre-bid and Post-bid Phases

  • Pre-bid Phase: The header bidding script sends bid requests to demand sources, collects bids, and runs an auction to determine the highest bid.
  • Post-bid Phase: The winning bid is sent to the ad server. Ad Server then updates the winning bid in the analytics and displays the ad on the ad slot using its ad-serving logic.

The Role of User Data

The user data is part of the bidding process, allowing selection of certain audiences based on their characteristics: age, interests, and behavior. Through cookies and pixels, the bid of demand sources can be adjusted according to the relevancy and the revenue. However, acts like GDPR and CCPA permit data and personal information to be handled responsibly and only with permission, data anonymization.

Key Components of Header Bidding

1. Header Bidding Wrappers

Header bidding wrappers are JavaScript libraries that sit on publisher websites and enable them to connect with demand sources like SSPs, DSPs, Ad Networks, etc. They help in orchestrating the entire auction using the below steps.

  • Manage the setup
  • Bids collection
  • Ads creative placement

Popular wrappers like Prebid.js and Amazon TAM are used to standardize and simplify the integration of multiple demand partners.

These wrappers streamline bid requests and ensure that all the demand sources can participate in the auction. By connecting all the demand sources wrappers improve transparency and competition in the auction process.

2. Ad Exchanges and Ad Networks

Nowadays in adtech, it’s hard to differentiate between Ad Exchanges, Ad Networks, DSPs, and SSPs as companies are doing all types of activities. Some differences in the process are still there. Ad Exchanges & Ad Networks aggregate demand and connect to supply.

  • They connect various advertisers and DSPs.
  • They aggregate the demand and help in facilitating real-time bidding b/w publishers and advertisers.
  • The real-time bidding ensures everybody gets the benefits 
    • Advertisers get the best-performing slot for their ads. 
    • Publishers get the best rates for their ad slots.

Ad exchanges and ad networks work hand-in-hand with wrappers to process bids quickly and efficiently.

3. JavaScript Implementation

Header Bidding relies heavily on JavaScript implementation, it executes bid requests and collects responses within the user’s browser. It’s crucial to implement JavaScript to ensure maximum profit.

  • Proper optimization of JavaScript ensures more demand sources can participate, maximizing revenue for publishers
  • To ensure a seamless auction, enable faster page load time & reduce latency.

Each component of header bidding like wrappers, ad exchanges, and networks interacts through this JavaScript infrastructure, to drive efficient and competitive auctions.

Header Bidding Architectures

Header bidding can be implemented through two primary architectures: client-side and server-side.

Client-Side Header Bidding: In client-side header bidding, the bidding process happens within the user’s browser. It is executed by a JavaScript wrapper. It sends bid requests to demand partners, then collects bids, and auction the ad slot based on bids and predefined configuration using RTB. While this method provides transparency and control, it may cause latency and scalability issues, as multiple requests must be processed by the browser.

Server-Side Header Bidding: Provided the Client Side Header Bidding issues, server-side header bidding was introduced. It uses a server to perform the bidding. The browser sends one request to the server, which then handles bid requests to demand partners and returns the highest bid to the browser. This reduces latency and improves scalability but can reduce transparency and control over the bidding data.

Tools to Check Behind the Scenes of Header Bidding

Developer Tools

  • Chrome DevTools: Chrome DevTools is a fundamental yet crucial tool for monitoring and troubleshooting header bidding processes. It allows tracking of bid requests and responses in the Network tab, identification of JavaScript errors in the Console tab, and performance analysis in the Performance tab.
  • Requestly: A browser extension that simplifies ad operations troubleshooting. Requestly intercepts and modifies HTTP/HTTPS requests, allowing you to fix malfunctioning ads, simulate geo-targeted campaigns, and test custom ad experiences. It also supports testing Prebid.js configurations in staging environments to catch issues early.
  • Charles Proxy: A desktop-based application that works similarly to Requestly. It can monitor and debug HTTP/HTTPS traffic. It includes features like bandwidth throttling, session recording, and request/response inspection.

Analytics and Reporting Tools

  • Prebid Analytics Adapter: Built into Prebid.js, this tool sends auction data to analytics platforms and tracks key metrics such as bid responses and win rates. It helps publishers optimize their header bidding strategies in real time.
  • Professor Prebid: A specialized tool for Prebid users, providing detailed insights into header bidding performance metrics like win rates and revenue impact.
  • Google Ad Manager: Google Ad Manager is widely used by publishers for tracking ad performance, impression data, and auction outcomes, offering a comprehensive view of header bidding activities.

Maximizing Revenue Through Optimized Header Bidding Strategies

Header bidding is crucial when it comes to generating maximum revenue with the help of better ad placements. Knowing how it works, how to make it faster and more efficient, and which tools to use, ad ops professionals can reach its full potential. Staying updated on best practices will be key to maintaining a competitive edge in the evolving ad tech landscape.