Header bidding is a technique where the publisher offers the same ad impression, to multiple ad exchanges, simultaneously. Once the highest bid is selected, it is sent on the ad server and the chosen creative is displayed. The idea is that by letting multiple demand sources bid on the same inventory at the same time, publishers increase their yield and make more money.
Relevant Digital has been working with several header bidding solutions together with our customers, in different ad-server platforms. Usually Relevant handles the building of the prebid.js library and the code that will call different demand partners. We also educate publishers ad-ops team and developer team in how to implement the header bidding solution.
The customer’s ad-ops and tech team are executing the implementation and debugging of the prebid.js code on the website and building of the header bidding line items in the publishers ad-server. Relevant Digital is of course assisting and supporting as much as needed. Each project is different because of amount of websites, placements, type of ad server and number and types of SSPs. But investment will be paid back in few months, so building header is definitely worth of the investment!
So how does PREBID work?
At a high level, header bidding involves these steps:
1. The ad servers tag on page is paused, bound by a timer, while the Prebid library fetches bids and creatives from various SSPs & exchanges you want to work with.
2. Prebid passes information about those bids (including price) to the ad servers tag on page, which passes it to the ad server as query string parameters.
3.The ad server has line items targeting those bid parameters.
4. If the ad server decides Prebid wins, the ad server returns a signal to Prebid telling the library to write the winning creative to the page. All finished!
The Prebid library is composed of two pieces: the Core wrapper code and the Adapters a publisher wants to work with.
Our priority one recommendation is usually to build a Client Side Header – solution, but in some cases, lighter solution like the Post-Bid solution are justified. Relevant Digital has executed several prebid.js Post-Bid solutions together with our customers in different ad server platforms.
Usually Relevant will build the prebid.js library and the code that will call different demand partners. This includes instructing the publishers ad-ops team on how to build the line item setup. The customers ad-ops team only needs to place Post-Bid call in to their ad-server. This project is not as demanding as the Client Side Header solution, but each project is different because of amount of websites, placement, ad-server and SSPs.
How does POST-BID work?
At a high level, Post-Bid involves these steps:
1. The webpage sends an impression to the ad server.
2. The ad server chooses a winning line item among class 1, exchanges, and the post-bid line items. In this case, the post-bid line item wins because the eCPM on the line item is high (based on historical price) and the higher priority class 1 line items have all exhausted their spend.
3. The post-bid line items creative is served to the page. The creative runs an auction for the bidders using prebid.js, which then displays the highest price creative in that creative’s ad slot.
In post-bid, the competition among your mediated demand sources compete AFTER your ad server has chosen the winning line item (vs. in header bidding, demand sources compete BEFORE your ad server has seen the impression). In post-bid, your mediated demand sources no longer run daisy chain; they all compete in one single line item based on price.
Header bidding vs Post-Bid
Header bidding vs Post-Bid Summary
- Client Side Header Bidding is called when the page loads before the adrequest goes into the ad server
- Post-Bid is called after the adrequest comes into the ad-server and the ad server has chosen the line item that contains the Post-Bid creative
- In both solutions the SSPs are called simultaneously with the prebid.js code (vs. waterfall where all partners are called separately and daisy chained with passbacks)
- Both solutions improves and simplifies the publishers programmatic setup by erasing the need for passbacks and creating a unified auction between different SSPs.
Relevant Yield is built with strong hands on experience in running programmatic ad operations. We are an independent company and a neutral, trustable and flexible partner. Our solution is highly customisable and continuous development is based on markets and customers' needs. Relevant Yield is the most comprehensive solution on the market for ad ops and digital sales teams to maximise revenue. You will get all in one package - revenue insights, real time analytics and remote control of prebid setups.
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