Header Bidding (HB)
A technique used by publishers to collect multiple bids from demand sources — including DSPs and ad networks accessed via SSPs and ad exchanges — simultaneously, rather than sequentially.
Publishers implement header bidding by inserting a wrapper tag inside the <head> of their website's HTML, which is where the name originates. When a page loads, this wrapper fires auction requests to multiple demand sources in parallel, gathering bids before the publisher's ad server is ever called.
The core objective is to surface the highest possible bid upfront, allowing outside demand to compete directly against a publisher's premium inventory and direct deals. This competitive dynamic benefits both sides: advertisers gain access to high-value inventory they might otherwise be locked out of, while publishers maximize their CPM and eCPM rates by ensuring every impression is contested at its true market value.
