IAB Tech Lab Shifts SPO From Shortest Path To Most Transparent

Buyers gain visibility into every company touching a bid request before it reaches a DSP, exposing infrastructure participants previously invisible in the schain object. This could reveal redundant intermediaries and duplicative bid requests that inflate costs without adding value. The change directly affects CTV and streaming ad tech stacks where SSAI platforms, SDKs, and wrappers are common — infrastructure that has operated outside payment-flow transparency. Companies including Amazon Ads, The Trade Desk, and Raptive have already voiced support. Watch whether SSPs adopt the hp=0 designation during the public comment period or push back on implementation complexity, and how quickly DSPs update parsing logic to handle longer schains.

The SupplyChain v1.1 proposal arrives amid intensifying scrutiny of programmatic supply chain economics. In a May 2026 blog post on IAB.com, Angelina Eng noted that research from the ANA, ISBA, and Jounce Media has repeatedly documented that a significant portion of every programmatic dollar fails to reach publishers, with working media efficiency estimates ranging from 50 to 57 cents on the dollar even among top-performing advertisers. Eng argued that existing transparency tools like ads.txt and sellers.json address identity but not economics, and called for standardized fee reporting and impression-level cost reconciliation.

Jounce Media's April 2026 Supply Path Benchmarking Report quantified the stakes: rebroadcasting supply chains — those where exchanges pay companies without exclusive sales rights — operated with a 50% monetization deficit compared to maximally direct paths. The report also found that 15% of bid requests independently identified as wasteful rebroadcasting were incorrectly labeled DIRECT in publisher ads.txt files, underscoring why self-declared transparency signals have proven insufficient.

The proposal has drawn explicit support from major players across the ecosystem. Per IAB Tech Lab's June 23 press release, Neal Richter, VP of Amazon Ads and Chair of the IAB Tech Lab Board, called the update "an important step forward," while Rob Hazan of The Trade Desk argued that "longer supply chains are not automatically worse supply chains" if every participant is disclosed. Chris Kane, Founder of Jounce Media, said the change brings the industry closer to distinguishing "value-added partners from unnecessary hops."

MarTech, in its June 23 coverage, noted that the shift could create winners and losers: companies delivering measurable value gain differentiation, while vendors unable to explain their role in the transaction chain face exposure. The outlet also reported that IAB Tech Lab expects schains to become longer as transparency improves, with rollout guidance recommending SSPs and DSPs coordinate staged testing before scaling.