Executive Summary

Header bidding, a specific implementation of programmatic advertising that allows ad buyers greater access to publisher inventory—even inventory once set aside for direct advertisers—is making it easier for ad buyers to access premium ad inventory. For publishers, granting such access is leading to higher CPMs.

Has header bidding reached maturity on the web?

Yes, more or less. More than half of US web publishers have adopted header bidding, and experts indicate header CPMs are beginning to stabilize. Growth will only continue when more buyers get used to first-priced auctions and adjust their strategies accordingly.

Which header bidding setups are publishers using today?

Publishers have three main ways to enable header bidding—as a standalone integration into their webpages, as a client-side wrapper (where one header-bidding partner acts as the container to house all others) or server-to-server (where the header auction happens off-browser and is instead passed from a single header partner’s server to the publisher’s ad server). Today, the greatest portion of publishers rely on client-side wrappers alone, or client-side wrappers plus another integration type.

How is header bidding affecting programmatic advertising?

In the past 12 months, header bidding has sparked interest in supply path optimization (SPO), which is a practice whereby ad buyers weed out unnecessary intermediaries in the supply chain. Now, many sell-side parties are looking to do optimizations of their own via demand path optimization. Header bidding has also introduced nuances to programmatic auctions that buyers must understand and be able to identify. Otherwise, they run the risk of doling out more dollars than necessary.

Will header bidding make it into video and apps, like everyone expects?

Most see a future where header bidding accounts for a greater share of app inventory. Today, difficulties with server-to-server setups and software development kit (SDK) integrations keep in-app header bidding at bay. Technical limitations also make it difficult to enable header bidding for video ads; however, today’s advertising economics don’t necessarily emphasize the value of header bidding for video ads, either.

WHAT’S IN THIS REPORT? This report looks at the latest trends surrounding header bidding and answers core questions about header bidding’s future in the next 12 to 24 months.

KEY STAT: The lion’s share of header-bidding impressions worldwide still occur within desktop, not mobile devices, according to H1 2018 data from PubMatic.