Glossary
DPO (demand path optimization)
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Demand path optimization is the sell-side mirror of SPO: a publisher or SSP choosing which demand sources, resellers and intermediaries to accept bids from, based on net revenue, fees taken between the advertiser and the publisher, bid quality and the cost of serving requests.
A publisher connected to many SSPs sees the same advertiser dollar arrive through several paths with different fees attached. DPO means measuring the net CPM per path, dropping paths that add fees without adding unique demand, and reducing the request volume sent to partners that rarely win. The data for this comes from the publisher's own log-level data joined with the buyer-side transparency that the ANA's benchmarks exposed: 43.9% of a DSP dollar reaching the consumer in 2024 and 45.1% in Q2 2026 (ExchangeWire, 16 September 2026).
The structural tools are the same as for SPO, read from the other side. ads.txt and sellers.json are the publisher's declarations; the SupplyChain object is what the publisher's wrapper or ad server stamps on each request; SupplyChain v1.1, in public comment to 21 August 2026, extends the chain to custody-taking entities such as Prebid, ad servers and SSAI platforms and marks them hp=0 (IAB Tech Lab, 23 June 2026). The US remedies ruling of September 2026, which requires Google to give Prebid and third-party ad servers real-time access to AdX bids, is in effect a DPO mandate; the tracker is at Google ad tech remedies explained for publishers.
Example: a publisher's analysis shows SSP C wins 2% of auctions but receives 30% of requests; it reduces C's request share and reallocates to SSPs with higher net win rates.
Related: SPO, SupplyChain object, log-level data, header bidding.
Source: IAB Tech Lab, SupplyChain v1.1 (June 2026); ANA benchmarks via ExchangeWire (16 September 2026).