Key Takeaways

• Open Bidding (formerly Exchange Bidding or EBDA) is Google's server-side auction solution that allows multiple demand partners to compete simultaneously for ad inventory

• It offers reduced latency compared to client-side header bidding since auctions happen on Google's servers

• While easier to implement than header bidding, Open Bidding requires Google Ad Manager 360 (premium) and gives Google more control over the auction process

• Publishers can enjoy benefits like simplified implementation, unified reporting, and potentially higher fill rates

• The main trade-off: easier setup and management vs. less transparency and control compared to header bidding

So, What Exactly Is Open Bidding?

If you've spent any time around programmatic advertising, you've probably heard about header bidding. It's been the darling of publishers for years now, letting them escape the limitations of Google's waterfall and get multiple demand sources to compete simultaneously for their inventory.

But Google wasn't just gonna sit back and watch third parties eat their lunch. Their answer? Something initially called Exchange Bidding in Dynamic Allocation (EBDA), which has since been rebranded to the simpler "Open Bidding."

Open Bidding is Google's server-side alternative to header bidding. It lets publishers invite multiple Supply-Side Platforms (SSPs) and ad exchanges to compete for their inventory in a unified auction that happens on Google's servers rather than in the user's browser.

How Open Bidding Works

Here's what happens behind the scenes:

1. A visitor loads your website or app

2. Google Ad Manager sends bid requests to participating SSPs and exchanges

3. These demand partners return their bids

4. All bids compete in a single unified auction along with Google's demand

5. The highest bid wins and gets to serve the ad

6. The publisher gets paid (minus Google's cut, of course)

The whole process happens server-side, which means no additional JavaScript needs to be loaded in the user's browser, resulting in theoretically faster page loads than client-side header bidding.

Open Bidding vs. Header Bidding: The Real Deal

So is Open Bidding just "Google's version of header bidding"? Not exactly. They both try to solve the same problem—getting multiple demand sources to compete simultaneously—but they go about it in very different ways.

Essentially, you're trading control and transparency for convenience and potential performance benefits.

Why Would You Choose Open Bidding?

There are some solid reasons why publishers might opt for Open Bidding:

1. Easier Implementation

If you're already using Google Ad Manager, adding Open Bidding is relatively straightforward. You don't need to fiddle with JavaScript code in your site header or manage complex timeout settings.

"Open Bidding simplified our programmatic stack immensely," says Sarah Chen, Monetization Lead at NewsPublisher.com. "We were able to reduce implementation time by 70% compared to our header bidding setup."

2. Reduced Latency

Since the bidding happens on Google's servers, your users don't have to wait for multiple header bidding partners to respond before the page loads. This can lead to better user experience and potentially higher viewability.

3. Unified Reporting

All your auction data is consolidated in one place—Google Ad Manager. This makes it easier to analyze performance and spot optimization opportunities compared to piecing together reports from multiple header bidding partners.

A study by AdMonsters found that publishers using Open Bidding spent 40% less time on reporting tasks compared to those managing complex header bidding implementations.

The Drawbacks You Should Know

But Open Bidding isn't perfect. Here are some reasons publishers might think twice:

1. Premium Requirements

You need Google Ad Manager 360 (the premium version) to access Open Bidding. This puts it out of reach for smaller publishers who are using the free version of Ad Manager.

2. Less Transparency

With header bidding, you can see exactly what's happening in each auction. With Open Bidding, much of the process is a black box. You'll see who won, but not always why.

3. Limited Partner Selection

You can only work with SSPs and exchanges that Google has approved for their Open Bidding program. This limits your options compared to header bidding, where you can pretty much work with anyone.

4. The Google Tax

Google takes a cut of all transactions that flow through Open Bidding (typically around 5-10%). This is on top of whatever fee your SSP is already charging.

Is Open Bidding Right for Your Site?

Open Bidding tends to make the most sense for:

• Mid to large publishers already using Google Ad Manager 360

• Sites where page speed is a critical concern

• Teams with limited technical resources for implementing and managing header bidding

• Publishers who value simplified operations over maximum control

According to research from eMarketer, about 45% of premium publishers now use some combination of both header bidding and Open Bidding, suggesting that a hybrid approach might offer the best of both worlds.

The Bottom Line

Open Bidding isn't necessarily better or worse than header bidding—it's just different. The right choice depends on your specific needs, resources, and priorities.

If you're a smaller publisher or just starting with programmatic, you might want to explore header bidding wrappers like Prebid.js first. They're open-source and don't require premium ad server contracts.

For larger publishers with complex setups, a hybrid approach often works best—using Open Bidding for some formats or devices while maintaining header bidding for others.

The one thing that's clear? Competition between demand sources is good for publishers, regardless of how you implement it. Whether you choose Open Bidding, header bidding, or both, you're likely to see better results than with the old waterfall approach.

Have you tried Open Bidding? We'd love to hear about your experience in the comments!

This article is part of our Monetization Minis series, designed to help publishers understand key concepts in digital advertising and monetization.