Behind the Bidstream: The Signals that Matter examines a problem that is increasingly costly for programmatic TV. Before an ad is served, a buyer’s demand-side platform reads the “bid request” for each advertising opportunity. That request carries information such as the app or service, the content, the device, available audience signals and the companies involved in selling the inventory. When that information is missing, inconsistent or unusable, buyers struggle to identify suitable inventory, and publishers struggle to attract demand for it. The study looks at US connected TV and streaming video, and asks which signals buyers require, where those signals are missing or unreliable, what causes the gaps, how the gaps shape buying behavior and seller outcomes, and what could improve transparency.
The evidence comes from three sources: a survey of 50 qualified programmatic CTV buyers, fielded in May and June 2026; interviews and discussions within CIMM’s Programmatic Working Group; and platform analyses supplied by co-sponsors FreeWheel and OpenX. Together they show that gaps arise for both legitimate and avoidable reasons. Privacy obligations, commercial choices and distribution agreements can limit what sellers disclose. Technical differences in how platforms pass along or process information can also leave signals missing or unusable as bid requests move through the supply chain.
The findings suggest that transparency is as much about trust as about volume. Buyers want richer signals, but they prefer limited information on a verified supply path to detailed information on an unverified, multi-hop one. When their requirements aren’t met, they more often switch supply paths or broaden targeting than lower their bids. Better signals can therefore improve a seller’s access to demand, though they don’t guarantee higher prices. Buyers also report real uncertainty about whether their platforms act on the signals they require: only 8% said their required signals are always used. The study recommends that buyers and sellers agree on signal requirements explicitly before trading. It also proposes shared tools to make delivery verifiable — a candidate trading baseline, comparable platform capability statements and reconciliation reports — to be tested through a voluntary industry pilot.
This paper was co-sponsored by OpenX and FreeWheel.
For the full Report: Click HERE
For a key exhibit from the Report – Minimum viable programmatic TV signal hierarchy: Click HERE
