Prebid Is The Key To Unlocking The Cookieless Future For Publishers

Rich Calkins OpenX

The Sell Sider” is a column written by the sell side of the digital media community.

Today’s column is written by Rich Calkins, Director of Product Management for OpenX. 

Publishers are right to be worried about the impact that third-party cookie deprecation in Chrome will have on their programmatic revenue.

In 2019, Google ran a study to quantify that impact and found that the top 500 publishers (in GAM) saw an average revenue decline of 52% and a median decline of 64%. The more reliant some are   on open-exchange programmatic revenue, the more vulnerable they’ll be.

To date, concrete “solutions” to this problem are still in short supply. Even those alternatives that have been proposed – I’m looking at you 27 (!!) Prebid User ID Modules – take significant effort to investigate, understand, integrate and test. Separating the signal from the noise is getting increasingly difficult for all parties in our ecosystem, but especially for publishers.

Prebid is more critical to the future of this industry than before. If you aren’t using Prebid yet, what are you waiting for? If you are, prepare yourself for a year of constant experimentation.

While much still remains in flux, we predict that hitching your horse to Prebid will help publishers plan for a cookieless 2022. Here are the key changes coming to Prebid that publishers should prepare for now:

Prebid.js + Prebid Server will become the new standard web integration

Today, bidder adapters are primarily integrated on page, through Prebid.js, which improves user match rates.

Moving bidders server side invariably decreases match rates, a negative side effect that’s hindered adoption of Prebid Server. However – and I think you see where this is going, without third party cookies, there is nothing to sync. This means it’s time to ship those bidder adapters over to the server-side.

You might be asking, should I start this process now? The answer is yes. If you are using five or more bidder adapters client side today, moving lower-performing bidder adapters server side can result in immediate UX improvements with limited impact to revenue.

In addition, investing the time and resources now to setup and optimize Prebid Server means you won’t have to scramble next year.


  • Pressure your demand sources to support Prebid Server: The list of Prebid Server adapters continues to grow, but there is still a decent gap between adapters in Prebid.js and Prebid Server. Ask your partners now if they support Prebid Server, and if they don’t, insist that they add it.
  • Choose where to run Prebid Server: The easiest and fastest way is to choose a Hosted Prebid Server provider. You can also set this up yourself, DIY style, in Go or Java.
  • Set aside time for implementation and testing: Setting up Prebid Server and configuring your server-side adapters will take time and coordination with various exchanges. A/B testing will help to figure out which adapters are best moved server-side now, and which can wait. You may have an experiment framework. If not, Prebid’s own js Module was designed for this process.

Set it and forget it is over, and rapid experimentation is the new normal

We surveyed more than 300 publishers earlier this year and found that 75% don’t update their Prebid configuration more often than monthly. Fifty percent update Prebid configurations quarterly, annually, or not at all. This is understandable, because Prebid takes time and resources to update, and you have other priorities. Maybe your revenue from Prebid isn’t very significant, so you forget about it, or just add a new bidder when you can.

Prebid already offers many features publishers will need in the cookieless future, and many more will be introduced or augmented before next year.

For example, if you’re wondering which of those aforementioned 27+ ID modules are right for you, experimentation, such as A/B testing, is a great place to start. With proper A/B testing and analytics, you can isolate performance on cookieless browsers (Safari, Firefox), looking at the difference between when the ID was available and when it wasn’t for outgoing bid requests.


  • Invest in an A/B testing framework: Make sure you have a quick and easy way to launch a/b tests for Prebid configuration changes, so that you can measure impact properly. Ideally this is on a small % of traffic to allow you to learn without putting revenue at risk.
  • Build or buy Prebid Analytics: All the A/B testing in the world won’t help if you can’t easily analyze the results. Many analytics solutions exist or you can build your own.
  • Keep Prebid up to date: New versions of Prebid.js launch every week. To take advantage of new features and bidder adapter updates, it’s critical to be on the latest stable version. (Just be careful of any breaking changes in major version releases.)
  • Stay in the loop on User ID Modules: Even if you have testing and analytics, sorting through all the ID modules requires serious time investment. We suggest following the money and prioritize ID solutions that have public backing from agencies and advertisers.

The cookieless future is uncertain and threatening. But real solutions and strategies are beginning to emerge. Prebid is at the center of all of it. While Prebid can be complex and time consuming, investing in it now will pay dividends later. Embrace the complexity, ask for advice and start to take action now.

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