Introduction
Programmatic advertising has greatly advanced since the days of manual ad placements and waterfall setups in programmatic advertising. As the digital ecosystem has matured, so have the ways in which we can maximize our ad revenue and efficiencies. Enter Google’s Open Bidding: a powerful innovative solution that aims to simplify and optimize the way publishers sell their inventory.
So what is Open Bidding? In simple terms, Open Bidding is server-side auction and allows multiple ad exchanges, networks, and demand partners to connect and bid on a publisher’s inventory in real time all within Google Ad Manager. Unlike traditional client-side methods, all the auctions are happening behind the scenes on Google’s servers – which decreases latency and makes the ad delivering a more seamless process.
But the increasing popularity of Open Bidding has led to confusion from advertisers and publishers alike about the Open Bidding process, especially in comparison with header bidding. While the terminology and technology may sound similar, they are two completely different processes, and work very differently behind the scenes.
In this guide, we’ll break down what Open Bidding is, explain how the open bidding process works, and explore its key benefits, potential challenges, and differences from header bidding. By the end, you’ll have a clear understanding of whether Open Bidding is the right strategy to help you boost yield and improve performance.
What is Open Bidding?
Open Bidding is an integrated, server-based auction in Google Ad Manager (GAM) that allows advertisers from any number of exchanges, supply-side platforms (SSPs), and demand partners to bid for a publisher’s ad inventory all at the same time. Instead of leveraging only one demand source, Open Bidding opens the door for transparency and competition while maximizing yield, ultimately allowing the highest bid to win.
Although it may sound like Google Ad Exchange (AdX), they are not the same. AdX is Google’s own exchange, limited to just buyers in their ecosystem. Open Bidding allows third-party exchanges and SSPs to compete for ad inventory, allowing for their external buyers to be part of the auction through the Google system. Thus, it’s a more varied competitive marketplace that eliminates the requirement of multiple integrations or adding additional code to the publisher’s site.
You may also hear Open Bidding referred to as Exchange Bidding in Dynamic Allocation (EBDA) — its original name when Google first introduced it. Despite the different terminology, the concept remains the same: enabling seamless, server-side competition among various demand sources to help publishers earn more while maintaining faster page performance.
How Does the Open Bidding Process Work?
To understand the open bidding process, it helps to look at how each step unfolds within Google Ad Manager (GAM). Unlike header bidding, which happens in the user’s browser, Open Bidding operates entirely on Google’s servers — making the process faster and more efficient. Here’s a simplified breakdown:
1. Publisher setup:
The publisher first enables Open Bidding in Google Ad Manager and invites preferred demand partners — such as third-party exchanges or SSPs — to participate in auctions. Each partner sets up pricing rules, deal terms, and latency limits within GAM.
2. Ad request triggered:
When a webpage loads, GAM automatically calls all participating exchanges at the same time. This replaces the browser-based scripts used in header bidding, reducing page latency and improving user experience.
3. Real-time bids submitted:
Each connected exchange analyzes the impression opportunity and returns its real-time bid to Google’s ad server within milliseconds.
4. Unified auction and ad serving:
GAM then runs a unified server-side auction that includes bids from Google AdX, Open Bidding partners, and direct deals. The highest bid wins, and the winning creative is served instantly to the page.
Because this auction occurs server-side, Open Bidding significantly reduces load time and operational complexity for publishers. There’s no need for multiple browser tags or complicated header scripts — everything happens seamlessly within Google’s infrastructure.
Continuous Open Bidding Explained
Continuous Open Bidding is the practice of permitting many ad exchanges, networks, and supply-side platforms (SSPs) to take part concurrently in an open bid. Continuous Open Bidding is a real-time auction process where every available ad impression competes in real-time for business and all eligible advertisers can bid at the same time.
This ongoing auction establishes an active marketplace where all demand partners compete for all available impressions without experiencing logging or cache bidding. When bids happen in real time, the publisher’s ad inventory automatically follows the highest-priced ad at that moment. Continuous Open Bidding helps the publisher increase yield as buyers compete for the same impression and ad users get audience at premium market rates.
In practice, continuous open bidding is mainly used by large publishing, media networks, and enterprise content platforms that control large inventories. In these cases, the process described above benefits from Google’s server-side process to manage the connecting of multiple partners while maintaining lower latency and page load time during the bidding process.
In short, continuous open bidding keeps the competition alive for every impression — helping publishers capture more value while maintaining a seamless ad delivery experience for users.
Open Bidding vs. Header Bidding
Although both Open Bidding and Header Bidding aim to increase competition for ad inventory, they differ significantly in how and where their auctions take place. The main distinction lies in the auction environment — server-side for Open Bidding and client-side for Header Bidding.
Here’s a quick comparison:
| Aspect | Open Bidding | Header Bidding |
| Auction Type | Server-side auction run within Google Ad Manager | Client-side auction executed in the user’s browser |
| Latency | Lower — handled by Google’s servers, reducing page load time | Higher — browser loads multiple scripts, which can slow pages |
| Transparency | Moderate — auction handled by Google, less visibility into bids | High — publishers can see and manage every bid directly |
| Control | Limited — Google manages integrations and reporting | Greater control — publishers configure partners and bid logic |
| Setup & Maintenance | Easier — single integration through GAM | Complex — requires technical setup and ongoing management |
Although Header Bidding provides more transparency and control, it also comes with a higher page latency and is more complicated to manage. Open Bidding, on the other hand, provides the same auction capabilities as Header Bidding, but is easier to manage, faster to deliver, and allows for successful ad delivery through their Google servers.\n\nSince there are different benefits for both options, many publishers implement a hybrid approach – utilizing Header Bidding for a few high-value demand partner(s), and also have Open Bidding to expand their reach and efficiency of ad delivery. This allows publishers to maintain a level of transparency while also focusing on performance to achieve maximum revenue while not compromising site speeds. \n\nIn summary, Open Bidding places emphasis on ease of use and efficiency, whereas Header Bidding places emphasis on transparency and control. The decision between the two, or a combination of both will depend on a publisher’s technical capacity of implementation, ad strategy, and performance.
Benefits of Open Bidding
The benefits of Open Bidding extend beyond just higher revenue — it’s designed to make the entire programmatic process smoother, faster, and easier for publishers to manage. By moving the auction to Google’s servers, Open Bidding eliminates many of the inefficiencies found in traditional setups.
1. Reduced latency and faster page loads
Because Open Bidding operates server-side within Google Ad Manager, the user’s browser doesn’t need to handle multiple auction scripts. This results in faster page load times, better user experience, and improved Core Web Vitals — all of which contribute to stronger SEO performance.
2. Simplified setup and management
Open Bidding is fully integrated into GAM, meaning publishers can onboard new demand partners directly within their existing workflow. There’s no need to add complex header code or maintain separate SSP integrations.
3. Access to multiple exchanges
Publishers can connect to a wide range of third-party exchanges and SSPs, creating greater competition for each impression. More bidders typically lead to higher CPMs and increased overall yield.
4. Unified billing and reporting
Google consolidates all Open Bidding demand partners into a single billing and reporting system, simplifying reconciliation and performance analysis.
Limitations & Challenges of Open Bidding
While Open Bidding offers efficiency and simplified management, it comes with certain challenges and limitations that publishers should be aware of before fully relying on it.
1. Revenue share
One of the most notable drawbacks is that Google takes a percentage of the ad revenue earned through Open Bidding. Although the platform increases competition and CPMs, the revenue share reduces the total payout to the publisher compared with running some direct deals or managing their own header bidding setup.
2. Reduced transparency
Because auctions occur server-side, publishers have less visibility into how bids are placed, which demand partners participate, and detailed bid dynamics. Header bidding, in contrast, offers more granular control and insight into every bid.
3. Dependency on Google Ad Manager
Open Bidding is fully integrated into GAM, meaning publishers must rely heavily on Google’s infrastructure. Any technical issues, policy changes, or delays in GAM can directly impact the auction and ad delivery.
4. Limited direct deals
Some advertisers prefer negotiating direct deals or programmatic guaranteed arrangements, which may be less flexible within Open Bidding. Publishers who rely heavily on premium deals may need to balance Open Bidding with other monetization strategies.
In summary, while Open Bidding streamlines the open bidding process, publishers need to weigh the trade-offs in revenue share, transparency, and dependence on Google when deciding how much of their inventory to allocate.
Real-World Examples of Open Bidding
Understanding Open Bidding becomes easier when we look at how it works in practice. Many publishers and advertisers have leveraged this server-side auction model to improve efficiency, increase revenue, and access premium inventory.
1. Large Publisher Success
A major media publisher implemented Open Bidding by connecting multiple SSPs through Google Ad Manager. Within months, the publisher saw a noticeable increase in CPMs, as the unified server-side auction allowed multiple exchanges to compete for each impression. By automating the bidding process, the publisher also reduced page latency and simplified inventory management, demonstrating the tangible benefits of Open Bidding for high-volume sites.
2. Hybrid Setup
Some publishers prefer a hybrid approach, running both Open Bidding and Header Bidding simultaneously. In this setup, high-value partners participate in header bidding for transparency and control, while other exchanges compete via Open Bidding to maximize competition and fill rates. This combination allows publishers to balance performance, revenue, and operational efficiency.
3. Advertiser Perspective
From an advertiser’s viewpoint, Open Bidding provides access to premium inventory that may otherwise be siloed across different exchanges. The unified auction enables advertisers to bid in real time alongside other demand partners, ensuring competitive pricing and broader reach without dealing with multiple integrations.
Best Practices for Implementing Open Bidding
Implementing Open Bidding effectively requires a strategic approach to maximize revenue and maintain smooth ad operations. Here are some proven best practices to follow:
1. Start with key demand partners
Identify and onboard reliable SSPs and exchanges that align with your inventory and audience. High-quality demand partners help ensure competitive bids and higher CPMs from the outset.
2. Compare performance with header bidding
Even if you fully adopt Open Bidding, it’s important to regularly benchmark performance against header bidding. Monitoring differences in revenue, latency, and fill rates helps identify areas for improvement and ensures you’re not leaving value on the table.
3. Use a hybrid setup to test yield
Consider running a hybrid model, combining Open Bidding with header bidding for select partners. This approach allows you to test which method generates better yield for different segments of your inventory, while balancing transparency and speed.
4. Optimize reporting and billing
Take advantage of Google Ad Manager’s reporting tools to track performance metrics across all Open Bidding partners. Unified billing simplifies reconciliation, and detailed analytics can highlight trends, underperforming partners, or opportunities to adjust floor prices.
5. Monitor latency and user experience
Although Open Bidding reduces page load times, publishers should continuously monitor site performance to ensure optimal user experience alongside revenue optimization.
The Future of Open Bidding
The programmatic advertising ecosystem is undergoing rapid evolution, and Open Bidding is expected to play a greater role. One factor driving this is the growing transition to server-side auctions which publishers can use to better comply with privacy regulations, decrease page load time, and ease the ad serving process – all considerations in our digital world today. In addition, as Open Bidding continues to grow, the adoption of demand partners is likely to increase, creating even greater competition for impressions, which is advantageous to publishers via higher CPMs, and advertisers in gaining access to premium inventory in real-time.
A second trend that seems to be emerging is the introduction of AI bidding optimization. Using machine learning, both demand partners and publishers will be able to optimize bids as well as predict user behavior and dynamically adjust floor prices. Overall, this will lead to faster and smarter auctions while concentrating on efficiency.
At the same time, independent header bidding wrappers remain a potential competitor, in that they offer some transparency and control that some publishers may still find valuable. Hybrid approaches that combine server-side Open Bidding with some elements of header bidding may, in the future, be more common, allowing publishers to weigh speed, revenue, and transparency with ad demand.
Final Thoughts
Open Bidding has become a compelling option in programmatic advertising — a single, server-side auction inside Google Ad Manager where multiple exchanges and SSPs compete, in real time, for each impression. For publishers, it means improved yield, easy setup, and less latency; while for advertisers, it offers access to premium inventory without managing multiple integrations.
However, it’s also important to balance Open Bidding against header bidding when transparency and control are most important. A lot of publishers find that a hybrid approach maximizes revenue and enables transparency and control over bid dynamics for their inventory.
In an ever-evolving digital advertising ecosystem, largely impacted by privacy regulations, faster page experiences, and advancements in AI to improve the optimization of ad experiences, keeping Open Bidding top of mind and understanding will be critical for both publishers and advertisers to leverage performance and ultimately get the most return on investment.
Frequently Asked Questions (FAQ)
Q1: What is Open Bidding in Google Ad Manager?
Open Bidding is a server-side auction within Google Ad Manager where multiple ad exchanges and SSPs bid on a publisher’s inventory in real time. This system allows publishers to maximize revenue while reducing page latency compared to client-side auctions.
Q2: How is Open Bidding different from Header Bidding?
The main difference lies in where the auction takes place. Open Bidding occurs server-side, which is faster and easier to manage, while Header Bidding happens client-side in the user’s browser, offering more transparency and control for publishers.
Q3: Is Open Bidding better for publishers?
It depends on a publisher’s goals. Open Bidding helps reduce latency and simplify ad operations, but Header Bidding provides greater control and visibility into bids. Many publishers choose a hybrid approach to balance both benefits.
Q4: What is continuous open bidding?
Continuous Open Bidding refers to the real-time, ongoing participation of multiple exchanges in each auction. Every impression is exposed to live competition, ensuring maximum yield for publishers.
Q5: Can Open Bidding and Header Bidding be used together?
Yes. Many publishers run hybrid setups, combining server-side Open Bidding with selective Header Bidding partners. This strategy allows them to maximize revenue while maintaining control and transparency where needed.
