Programmatic · also called first-party ad server, sell-side ad server
Publisher ad server
A publisher ad server is the system a website, app or streamer uses to manage its ad inventory and decide, for every ad slot, which campaign or programmatic buyer gets the impression.
The publisher ad server is the publisher's central brain for ads. It holds the ad units, the direct-sold advertising campaigns from insertion orders, the programmatic connections, and the rules for choosing between them: priorities, floors, targeting and pacing. Every ad request from the page goes through it.
Google Ad Manager (formerly DoubleClick for Publishers, DFP) is by far the most widely used. Others include Equativ, Kevel, FreeWheel (strong in premium TV and video) and Microsoft's Xandr Monetize. Many publishers run header bidding first and pass the best bid into the ad server as a line item, or use server-side approaches such as Google's Open Bidding.
In the United States v. Google ruling, the court found Google had monopolised the publisher ad server market and tied it to AdX, helped by features such as dynamic allocation and last look.
Think of it like this
A publisher ad server is like an airline's seat-booking system: it knows which seats are pre-sold to corporate contracts and which can go to the highest last-minute bidder.
An example
A European publisher's ad server receives the Prebid winning bid of €3.10 as a line item and compares it with AdX and a sponsorship campaign before choosing the ad.
Related terms
Ad server
An ad server is the software that stores ads, decides which ad to show in each slot based on rules and priorities, delivers it, and counts impressions and clicks.
Advertiser ad server
An advertiser ad server is the system brands and agencies use to host their ad creatives centrally, serve them into publishers and DSPs, and track delivery and results across all of them.
Dynamic allocation
Dynamic allocation is a Google Ad Manager feature that lets Google's ad exchange compete in real time against a publisher's other non-guaranteed campaigns for each impression.
Header bidding
Header bidding is a technique where a publisher offers each ad impression to many SSPs and exchanges simultaneously before calling its ad server, so all buyers compete at once.
Direct-sold advertising
Direct-sold advertising is ad space sold by a publisher straight to an advertiser or agency through a negotiated deal, usually with a fixed price and guaranteed volume.