Header bidding, love it or hate it, has been around for a few years and shows no signs of letting up. It is a slightly complicated piece of technology, made harder to comprehend for a neophyte unravelling the marvelous world of post-Google-AdWords advertising technology.
To understand header bidding, it’s critical to understand the old method of ad delivery to a publisher’s website and the evolution of adtech since real time bidding (RTB), Direct Buy.
Direct Buy’s are typically bulk purchases made by the publisher’s marketing team and the terms are negotiated before launch. The entire process is manual, prone to errors and takes up a lot of hours and must be managed by a person or a team.
Real-time bidding is programmatic, requires no human interaction and can serve ads customized to each site for multiple sites at the same time.
Visitor loads page – Publisher site calls ads from – Ad server (Direct buy’s) Often negotiated by the publisher themselves.
Now, all ad space on the site is made available via an ad server like Google Double Click for Publishers (DFP). This triggers a waterfall sequence, affectionately called so because the available ad space is offered first to Direct Buy’s which are most profitable to the publisher. If enough page views are generated, it may hit the threshold for Direct Buy’s, post which the ads are sourced via real time bidding/auction where swarms of advertisers will bid (programmatically) to serve ads from their own pools. This is your typical ad buy/serve sequence.
Header bidding takes place outside the programmatic ad platform, in the header of a web page. A header element of a web page loads first, and is the element for introductory content like metadata, CSS and tracking codes. This positions the header as a great place to provide enough information for an auction or bidding to take place. The advertiser has all he/she needs to know on what type of content the page serves to decide the ad category and type they will serve.
The actual bidding process starts as soon as the page loads, the header bidding code loads and the visitor’s browser reaches out to demand side partners querying their bids.