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Header Bidding Wrappers 101

The days of the inefficient waterfall are over: header bidding adoption among the top 1,000 publishers is up around 80%, according to the latest report from Adzerk. Now the go-to ad-selling tactic for publishers, header bidding has been around since late 2014 and has quickly become one of the hottest buzzwords in the industry. But, managing header bidding successfully and efficiently is easier said than done—the key is to use a header bidding wrapper, which we uncover in this post.

What is header bidding?

From Digiday’s WTF series, “header bidding is a programmatic technique wherein publishers offer inventory to multiple ad exchanges simultaneously before making calls to their ad servers... By letting multiple demand sources bid on the same inventory at the same time, publishers increase their yield and make more money.”

Publisher pitfalls with header bidding

Although header bidding can help publishers increase advertising revenue, it’s not without its drawbacks. Initial implementation and ongoing management requires a lot of internal resources because it is a manual process to add, remove, or update tags from demand partners. This quickly becomes tedious for IT departments because the code from each partner must be added or updated on every page owned or operated by a publisher.

Additionally, because of the mechanics of header bidding, traffickers need to set up hundreds or thousands of line items in their ad server to record bids from each demand partner. Each bid solicided in the header is passed to the ad server as a line item and then the highest bid is selected and rendered for the user. The more line items created during set-up, the greater the granularity in the ad server, which allows the server to best select the highest bid.

    Conversely, ad ops teams can make less work for themselves by setting up line items that target a range of values, $0.50 to $1.00 for example, instead of exact values. However, in this case an ad server would not know to select a bid of $0.75 over a bid of $0.60 because the bids would each come to the server as equivalent line items (any value falling between $.50 and $1) and the server would select between the two line items at random.

    Setting up thousands of line items at penny increments may not be the most efficient use of time for ad ops teams, but it will mean that the server always chooses the highest bid. The ideal blend of work and revenue is probably a combination of many line items where you have lots of bids and wider ranges for line items that serve less often.

Increased revenue is often enough of a draw for publishers to decide to adopt header bidding, regardless of the cost and hair-pulling that IT and ad ops teams will have to endure. But this doesn’t have to be the case—the solution is to implement a header bidding wrapper.

How header bidding wrappers streamline ad ops

Header bidding wrappers make set-up and management of the entire header bidding process much more efficient. Wrappers are like tag management systems that allow publishers to organize any number of demand partners and to set the rules for running the auction (most importantly, a centralized timeout). The wrapper triggers asynchronous ad calls to each demand partner so the rest of the page can load without issue, and wrappers make the problem of line-item creation simpler by translating specific values from each partner into a common parameter for the ad server.

The mechanics of header bidding wrappers

    1. A user opens a webpage, which includes the wrapper’s code.
    2. The wrapper sends bid requests to demand partners simultaneously
    3. Demand partners respond by giving their bids (after running their own auction)
    4. The wrapper sends the bids to the ad server
    5. The ad server chooses the highest bid and displays the ad to the user


Publisher Tip: Publishers can check on their current header bidding implementation, as well as identify how other publishers have theirs set up, by using a browser plugin like Headerbid Expert for Google Chrome, which shows all demand partners and their response time.

Below is an example from ESPN.com.



Key wrapper features and benefits

Implementing a wrapper will drastically improve your ability to monetize programmatically, especially if you plan to work with multiple demand partners, here’s how:

    Ability to set a central timeout: This protects you and your users from demand partners that return bids slowly. This feature also makes it much easier to test your timeout setting (only one location to update vs. updating the code on each page).

    Asynchronous container: Makes calls to all partners at the same time to create a “unified auction” (this is the main improvement and difference over the traditional waterfall). The user doesn’t have to wait for ads to load in order for site content to load.

    Easily add or remove demand partners: Instead of having to add and manage the code for each one individually, wrappers make managing multiple demand partners work at scale by eliminating a lot of painful setup work and centralizing code management.

    Analytics and benchmarking: Wrapper vendors often offer their own proprietary benchmarking and analytics tools as well as allow publishers to add their preferred analytics vendor to their wrapper for deeper analysis of their auction.

    Simplified line item creation: Most wrapper vendors, including the open source Prebid.js, help you create line items in your ad server through automation or reducing the number of line items required.

Key considerations

Investing the time and resources to implement a wrapper pays off in the long run but be sure to consider what is needed to get your wrapper up and running.

    Complex setup: Running any kind of header bidding implementation (with or without a wrapper) requires technical resources to set up, manage, and monitor. You’ll also want to spend time to understand how the wrapper works, what it supports, and what it doesn’t. Each wrapper will require a fair amount of time to set up initially, but this is usually a worthwhile investment in the long run. Keep in mind that there are managed services that can handle set-up and management, which we will cover a little later in this post.

    Wrapper stickiness: Using a wrapper makes demand partners less sticky because it’s easy to add or remove partners. The same does not go for the wrapper itself—each wrapper has its own implementation and once your site and ad server have been configured to support the wrapper, it can be costly and difficult to repeat the implementation process with a new vendor.

    Cost: There is a full spectrum of header bidding wrapper product options, from proprietary to open source to fully managed options. Obviously, the in-house and open source options only take internal resources to set up and manage. Managed options from exchanges are often free (often taking a cut of the demand they bring) though some charge a flat monthly fee for support.

    Fair auction: Wrappers hold auctions and pick winners so it’s important to make sure the auction is fair and doesn’t favor one exchange over another (one of the main reasons header bidding was developed).


Picking the right wrapper type

As mentioned above, there are a number of different wrapper configurations available to publishers: open source, proprietary, and managed solutions based off of proprietary and open source code. Deciding on the right fit depends on what internal resources you have available and what you need from a features and fit standpoint. Review what each type offers to begin your vendor research.

Top 10 client-side wrappers




Source: Adzerk Header Bidding Industry Index, August ’19 Report

Open source

The most popular option in the industry is the free and open-source Prebid.js with just under 26% adoption. Prebid.js provides a simple and easy to implement code set to improve header bidding for display and video ads on a publisher’s website and within OTT applications. It can be customized for each publisher and supports 150+ demand sources, 15 analytics adapters, currency conversion, GDPR, common ID systems, and multiple ad servers. Some publishers prefer Prebid.js because as an open source solution, it’s more neutral than a proprietary solution (and less likely to favor one partner over another). Prebid.js also simplifies line item creation in your ad server.

The main downside of implementing Prebid.js code is that it is relatively complex and will require internal resources to set up and manage, unless you opt for a managed solution. But, as with most open source projects, there is a large and active community of supporters that constantly work to improve the code, build new features, and develop knowledge bases.

In addition to Prebid.js, there is Prebid Server, an open-source solution for server-side setups (an alternative to client-side, discussed more in detail in a later blog post), and Prebid Mobile, for iOS and Android mobile apps.

Proprietary solutions

The second most popular wrapper in the industry (at 23% adoption) is offered by Index Exchange which uses their own proprietary code. Wrappers that use their own code have come under attack for possible bias toward certain exchanges (usually the exchange that built the wrapper), so Index Exchange has created a Wrapper Ecosystem to show the inner workings of their wrapper, report on partner performance, and simplify the bidder certification, maintenance, and deployment process. Depending on your needs, going the non-open source route may provide a better fit with your tech stack and offer particular features or configurations that are necessary for your operations.

Managed solutions

Most publishers don’t have unlimited dev resources so it makes a lot of sense to go with a managed service for your header bidding wrapper. Interestingly enough, there are managed services built on Prebid.js as well as on proprietary code (FYI, 64% of all wrapper solutions are based on Prebid code). Regardless of the code used, managed services can provide initial implementation support and ongoing management, which eases the developer burden on publishers. There may be some fear around transparency, so it’s important to review the audit capabilities of each vendor to ensure a fair auction. Also, keep in mind that there are costs to consider. Although open source solutions are free to use, they require internal IT/dev resources. Similarly, non-open source options may charge a set-up fee in addition to a rev share in exchange for the additional service and support offered.

Client- vs. server-side wrappers

This is another important consideration, which we won’t get to in this post, but will dive into in a future post—keep your eyes out!


To wrap up

Header bidding is an essential programmatic technique for generating the most revenue from your inventory. However, to fully realize the additional revenue, you must work with and test out multiple demand partners—and implementing a wrapper is the most efficient (and only) way to do so. Consider what you need from an operational and technical perspective and what resources you have available, then rely on this guide to help direct you where to look for the best solution.


If you’re interested in learning more about header bidding or how to manage all of that programmatic data once you have a wrapper implemented, contact us ›

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