Bid Request: Everything You Need to Know

Updated on: December 20, 2023
Explore the role of bid requests in providing a seamless ad experience for users while maximizing ad revenue for publishers.

As a publisher, striking the perfect balance between ad revenue and user experience can be challenging. That’s where bid requests come to the rescue, ensuring your audience is served with relevant, engaging ads while maximizing profits.

These essential tools have become indispensable in online advertising, helping publishers and advertisers alike navigate the complexities of ad buying and targeting. By understanding how bid requests work, you can unlock their full potential and drive success for your website.

In this comprehensive guide, we’ll uncover bid requests’ vital role in various ad-buying processes and how they adapt to the post-third-party cookie landscape. We’ll also delve into the bid request process, the data collected, and the importance of ad relevance in the user experience.

What is a Bid Request?

Let’s put on our detective hats and dive into the nitty-gritty of bid requests, shall we? 

A bid request is a piece of code that activates when visitors arrive at a webpage containing ad spaces. The primary objective is to collect valuable information about the user, such as their browsing behavior, interests, demographic details, and details about their device. This data enables demand partners to serve the most relevant and personalized ads possible to the user.

Think of it as your personal advertising matchmaker!

Let’s break down how they help in various programmatic auctions:

  • Real-time Bidding: In the blink of an eye (well, milliseconds, actually), a bid request is sent from your website to the ad exchanges and SSPs, sharing valuable information about your website visitors with advertisers.

 They then battle it out, placing bids based on the user data provided. The highest bidder gets to display their ad on your site.

  • Open Bidding: Also known as server-to-server bidding, this process sees multiple ad exchanges, SSPs, and ad networks bid on your inventory simultaneously. 

Bid requests enable these exchanges to access user information, ensuring the most relevant ads are served.

  • Header Bidding: This advanced programmatic technique involves a bid request sent to multiple demand sources simultaneously rather than one at a time.

The result? Increased competition and, you guessed it, more relevant ads for your visitors.

No matter the process, bid requests are the glue that holds it all together, ensuring a seamless and profitable ad experience for publishers and advertisers alike.

Information Contained in a Bid Request

Bid requests are packed with valuable data that helps advertisers serve relevant ads to users. Different elements that make up a typical bid request include the following:

  • Bid ID: This unique identifier helps keep track of each bid request, ensuring every bid is easily distinguished from others.
  • User Device: Here, you’ll find details about the user’s device, including the device type, model, operating system, and ISP.
  • User Details: It houses the user’s demographic information, such as location, age, gender, preferences, and browsing history. Advertisers use this data to tailor their ads to the user’s interests.
  • Impressions: This metric indicates the minimum number of ad impressions for banners or videos, as determined by the available inventory.
  • Extensions: This area highlights any additional inventory-related information that might be useful to advertisers or Demand-Side Platforms.
  • Website: This section covers the page context, content type, publisher ID, and domain name, among other details.
  • Application: If the ad inventory is for an app, the bid request will include information like the app ID, content type, and publisher ID.

While these elements are typically included in a bid request, changes in privacy regulations and phasing out third-party cookies may result in variations.

Bid Request in a Post-Third-Party Cookie World 

As third-party cookies are gradually phased out, advertisers and publishers must adapt their strategies for collecting user data and serving relevant ads. Contextual advertising and first-party data are becoming increasingly important in the post-cookie era.

Publishers can collect first-party data from their users through various means, such as registration forms, surveys, and user interactions with the website. This data can then be used in bid requests to help advertisers better target their ads, even without third-party cookies.

Contextual advertising focuses on serving ads based on the content of the web page rather than the user’s personal information. By understanding the context of a page and using contextual targeting, publishers and advertisers can still deliver relevant ads to users without third-party cookies.

Additionally, the industry is working on new solutions, such as Unified ID 2.0, which aims to provide alternative methods for user identification and ad targeting while respecting user privacy.

Best Practices for Publishers

As a publisher, you’re always on the lookout for ways to maximize your ad revenue while maintaining a delightful user experience. Bid requests play a vital role in achieving that balance. So, how can you optimize your bid requests and provide the most accurate information to secure higher bid rates?

1. Enhancing Bid Request Quality for Higher Bids

To boost your bid rates, focus on improving the quality of the information in your bid requests. The more data you provide to advertisers, the better they can target their ads, and the more likely they will place higher bids.

Optimize your bid requests by including detailed user information, ad inventory specifics, and additional data that may help advertisers make informed decisions.

2. Ensuring Data Accuracy in Bid Requests

Accuracy is key when it comes to bid requests. Be sure to validate the information you collect and keep it up-to-date. This can include periodically reviewing and updating user demographics, interests, and preferences and ensuring that your ad inventory details are current and relevant.

3. Leveraging Ad Format & Placement for Higher Bid Rates

The ad format and placement can significantly impact bid rates, as advertisers are more likely to bid higher for placements that offer better visibility and engagement.

Experiment with your site’s different ad formats, sizes, and placements to determine which combinations yield the best results. Continuously monitor and analyze the performance of your ad units to make data-driven decisions about ad placements.

4. Capitalizing on Audience Data

Audience data plays a crucial role in the bid request, as advertisers use this information to tailor their ads to users’ interests and preferences. Proactively collect first-party audience data through registration forms, surveys, and user interactions with your website.

By providing accurate, up-to-date audience data in your bid requests, you’ll help advertisers deliver more relevant ads, increasing the likelihood of higher bids and a better overall user experience.

Common Pitfalls and How to Sidestep Them

Navigating the world of bid requests can be tricky, but avoiding common missteps can help ensure a smoother and more successful process. Keep an eye out for these pitfalls as a publisher, and you’ll be well on your way to mastering the art of bid requests:

1. Steering Clear of Bid Request Rejection

Bid requests may be rejected for incomplete or inaccurate data, lack of user consent, or non-compliance with industry standards. 

To minimize the risk of rejection, ensure that your bid requests contain all necessary information, respect user privacy, and adhere to applicable regulations and best practices.

2. Evading Low-Quality Bid Requests

Low-quality bid requests can result in bad ad experiences for your users and lower bid rates for you. To avoid sending low-quality bid requests, focus on providing accurate, up-to-date, and comprehensive user data.

Make it a point to periodically review and update the information in your bid requests, ensuring that advertisers have access to the most relevant and valuable data possible.

3. Adhering to Industry Standards and Best Practices

Following industry standards and best practices is crucial for the success of your bid request strategy. Stay informed about the latest trends, technologies, and guidelines in online advertising, and actively implement them in your processes. 

This includes maintaining compliance with data protection regulations, obtaining user consent, and implementing measures like ads.txt to prevent ad fraud and unauthorized sales.

By avoiding these common mistakes and staying on top of industry developments, you’ll be better equipped to optimize your bid request strategy, enhance the user experience, and maximize your ad revenue.

The Takeaway on Bid Requests

Bid requests are essential for publishers seeking to strike the perfect balance between user experience and ad revenue. By understanding the intricacies of bid requests and implementing best practices, you can:

  • Optimize bid request quality for higher bids
  • Ensure data accuracy in bid requests
  • Leverage ad format and placement for higher bid rates
  • Capitalize on audience data
  • Avoid common pitfalls and mistakes

As you navigate the ever-evolving world of online advertising, bid requests will continue to play a crucial role in ensuring that your audience is served with relevant, engaging ads while maximizing your profits. 

Stay informed, adapt to industry changes, and continuously refine your bid request strategy to drive success for your website and deliver a seamless, delightful ad experience for your users.


What is bid request and bid response?

A bid request is a snippet of code activated when a user visits a webpage with ad spaces. It collects data about the user and device to help ad networks serve the most relevant ads. A bid response is the advertiser’s reply to the bid request. It contains information about the ad, such as creative, bid amount, and targeted user segment, allowing the publisher to select the highest bid and display the winning ad on their webpage.

What does a bid request contain?

A bid request typically contains valuable data that helps advertisers serve relevant ads to users, including bid ID, user device, user details, impressions, extensions, website, and application details.

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