Programmatic · also called DPO
Demand path optimization
Demand path optimization (DPO) is a publisher's or SSP's practice of prioritising the buyers and routes that deliver the most value, and cutting those that add cost without adding demand.
Demand path optimization is the sell-side twin of supply path optimization. Publishers and SSPs look at which DSPs, buyers and intermediaries actually bid, win and pay, and then shape their connections accordingly: which demand partners get bid requests, how many, and with what data.
In practice, DPO includes throttling bid requests to buyers that rarely bid (saving infrastructure cost), removing unnecessary resellers from ads.txt, favouring direct DSP connections, and building direct relationships with large buyers and agencies. Some publishers also use buyers.json and the DemandChain object to understand who is really on the other end.
DPO matters because of the explosion of bid requests after header bidding. Sending every impression to every buyer wastes money on both sides. The aim is fewer, better paths, which also reduces opportunities for traffic arbitrage and ad fraud to hide in the chain.
Think of it like this
Demand path optimization is like a farmer deciding which markets are worth driving to each week, based on who actually buys and pays well.
An example
An SSP stops sending bid requests to 40 DSP seats that bid on less than 0.1% of requests, cutting server costs by 20% with no measurable revenue loss.
Related terms
Supply path optimization (SPO)
Supply path optimization (SPO) is a buyer's practice of choosing the most direct, cheapest and most trustworthy routes to the same inventory, and cutting unnecessary resellers and duplicate paths.
SSP (supply-side platform)
An SSP (supply-side platform) is software that publishers use to sell their ad inventory automatically to many buyers, running auctions and managing prices, deals and quality controls.
buyers.json
buyers.json is an IAB Tech Lab standard in which DSPs and buying platforms publish a file identifying the buyer accounts ("seats") on their platform, helping sellers see who is really bidding.
Bid duplication
Bid duplication happens when the same ad impression reaches a buyer through several SSPs or resellers at once, so the buyer may bid against itself and waste processing and budget.
ads.txt
ads.txt (Authorized Digital Sellers) is a public text file on a website's domain listing which ad sellers and accounts are authorised to sell that website's ad inventory.