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Bidders in Pictures

Buying through Xandr

A bidder is a "decisioning brain" that calculates auction bids using an algorithm and some parameters, such as user data, recency, location, etc. Many of our clients use our hosted full-featured bidding system, Xandr's UI, which has built-in optimization and ad serving capabilities. Clients with existing in-house ad servers and sophisticated proprietary optimization logic may wish to build their own bidder. If you build your own bidder, you will host it on your own Xandr server or on another server in close proximity to our datacenters, and it will be owned and maintained by you. 

Selling Through Xandr


A TinyTag is a tag placed on a publisher's page. At the ad call, Xandr's impression bus looks up all information associated with the tag, such as a minimum acceptable reserve price and a reserve creative. The impression bus sends bidders the appropriate user and webpage information and asks for their bids in 1/20th of a second. If the reserve price is beaten, the highest bidder will win the impression. If no bidder meets the reserve price, and a reserve creative was specified, the reserve creative will be served.  

Preemptive Tags


The exact steps for PriceCheck will depend on the type of tag a publisher has on a page. In general, the ad call will be routed first to Xandr's impression bus, which will hold an auction based on the user and page information as described above. Bids are returned to Xandr's impression bus which then passes the highest bid to your adserver. The adserver can then decide how best to fill the impression; most commonly there will be another auction that includes the Xandr bid. If Xandr wins the impression, the ad call returns to our impression bus and the winning bidder serves the ad.


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