Programmatic
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.
Dynamic allocation was introduced in DoubleClick for Publishers (now Google Ad Manager). Before each impression was given to a non-guaranteed line item, the ad server checked whether Google's exchange, AdX, would pay more. If it would, AdX won the impression.
This boosted publisher revenue compared with fixed priorities, but it gave AdX a structural advantage: AdX could see the price of competing line items and bid in real time, while other exchanges could only submit historical averages. Combined with last look, this was a major reason publishers adopted header bidding.
Google later moved to a unified auction in 2019, and dynamic allocation now refers more generally to how Ad Manager lets AdX and other bidders compete with remnant line items. The practice featured in the United States v. Google case, in which the court in April 2025 found that Google unlawfully tied its publisher ad server to its exchange.
Think of it like this
Dynamic allocation is like a shop that lets one favoured supplier see all the other suppliers' prices before deciding whether to outbid them.
An example
A remnant line item is valued at US$1.20 CPM. Under dynamic allocation, AdX bids US$1.21 and takes the impression; another exchange that would have paid US$1.50 never gets a live chance.
Related terms
Last look
Last look is an auction advantage in which one bidder sees the best competing bid before bidding, so it can win by bidding just slightly more.
Unified auction
A unified auction is a single auction in which all demand sources, such as direct campaigns, header bidders and exchanges, compete for an impression under the same rules at the same time.
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.
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.
United States v. Google (ad tech)
United States v. Google (ad tech) is the US Justice Department's antitrust case in which a federal court ruled in April 2025 that Google illegally monopolised key open-web ad tech markets.
Sources: Google Ad Manager Help: Ad competition with dynamic allocation