We have previously discussed header bidding and prebid.js in-depth along with how they work in detail. The general consensus in the publisher community now is that setting up header bidding can be complex but it’s worth it—and it’s true. After discussing the header bidding wrapper, a container that organizes partners and sets rules for auction, it’s time we get to adapters, its uses, and the names of the most popular prebid adapters.

What is the Prebid Adapter?

A little recap, Prebid is a free open-source technology that offers a header bidding wrapper called Prebid.js. Once this Prebid.js is integrated into a publisher’s website, publisher can start adding demand partners and conduct auctions. But wait, how would publisher add a demand partner to the wrapper? The answer is using prebid adapter. Prebid adapter is the demand partner specific code that allows publishers to work with that demand partner and its partnered agencies and advertisers.

Still confused? Let us understand this with an example. Suppose, you, a publisher, want to partner up with AppNexus, OpenX, and Amazon. What will you do to get them onboard?. You will approach these companies and register with them. If these companies approve your inventory and agree to work with you, then you will be provided with a prebid adapter. This will be in the form of a code to be added in your wrapper.

In a nutshell, wrapper is a container and it contains adapters.

What is the Need for Adapter?

Adapter acts as a carrier for the demand side. After being added to the wrapper, it takes bid requests from wrapper to its respective demand partner. A demand-level auction is then conducted internally in the DSP and then it sends a qualifying bid response back to wrapper via the adaptor for further auction.

Furthermore, adapter carries the bid request containing details of the inventory and desired ad requirements (ad size, ad format, ad type). These details are important while looking for suitable advertisers to place bids on the publisher’s inventory. Here are some popular prebid adapters:

1. AppNexus

AppNexus created the open source prebid wrapper (Prebid.js) to call out multiple demand partners for publishers. That’s not it, AppNexus also offers a prebid adapter completely optimized for the prebid auctions. Next, AppNexus supports varied device and ad formats including video ads, mobile ads, and native ads. AppNexus features include transparent auctions, access to worldwide marketplace (including AppNexus marketplace), and advanced insight into bid dynamics, latency, and performance.

2. Rubicon Project

Rubicon Project is another well-known partner of the Prebid that actively contributes to publisher revenue worldwide. It is also built on the Prebid technology. Furthermore, it provides access to private marketplace and guaranteed deals to publishers. Along with the adapter, Rubicon also offers performance analytics and an account management team to understand the complexity of header bidding and run profitable auction every time. To further offer the best services, Rubicon is integrated with IAS, ComScore, Moat, and more, to provide best in class services for targeting, viewability, and measurement.

3. OpenX

OpenX has a fully optimized adapter for programmatic deals. It works on providing better CPM to publishers by connecting them to a large number of DSPs and advertisers. For publishers, OpenX brings dynamic bidding on the table which optimizes the value of every bid. Furthermore, it enables advertisers to leverage audience syncing technology on publisher’s inventory. And the control of each auction remains in publisher’s hand.

4. Index Exchange

Index Exchange is one of the high-paying demand header bidding adapters, especially for publishers operating in the US, UK, Canada, and Australia. Although it has its own wrapper, It offers proprietary Prebid based adapter too and due to its popularity, it has connections to many known SSPs and DSPs. For publishers, these connections can help them get the best price for their inventories. Also, when dealing in private marketplace, Index Exchange can help create connections to reliable advertisers.

5. Criteo

Criteo is a popular prebid adapter offering advanced retargeting features. It claims to provide transparent reporting stats with the demand partners. Criteo has worked with big companies like SurveyMonkey, XBOX, Adidas, P&G, etc. Using Criteo adapter, you can plug into Prebid as well as Index Exchange wrapper. With their claims to deliver unique demand, publishers can improve their CPMs.

What Else Should Publishers Know?

According to AdExchanger, in 2017, AppNexus and Index Exchange dominated the market as demand sources, with 44.8% publishers using AppNexus and 41.3% using Index Exchange, followed by OpenX (36%), Amazon (36%), AOL (33%), Rubicon (30%), Criteo (28%), Sovrn (26%), Sonobi (19%) and PulsePoint (17%) completing the top 10 list of header bidding adapters. (The number doesn’t add up to 100% because many publishers use more than one header bidding adapter.)

Chris Shuptrine, who created the report, explained, “The popularity of these companies’ wrappers and their adapters are linked. You don’t have to use AppNexus if you use Prebid, but the code is right there and built. You might as well use it. The same is true with Index Exchange being the largest third-party vendor wrapper solution.”

However, these are just numbers. When looking for an adapter to plug into the wrapper, publishers should put their requirements first (like what kind of ad format they want—display ads / native ads or both). Also, you as a publisher should know, adding more than 2-3 adapters can be beneficial in terms of fill rate and earned revenue but adding too many can increase page latency. Finally, testing is the key, make sure you run win rate, bid rate, and fill rate tests with your demand partners to improve earnings.

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