Ad tech tax

"Ad tech tax" is the informal name for the total share of an advertiser's programmatic spend that is absorbed by intermediaries and waste between the advertiser and the publisher, so that the publisher receives only the remainder.

The term has no owner and no formal definition; its content comes from audits. The ANA's benchmarks, as reported by ExchangeWire, split a 2024 DSP dollar into 43.9% reaching the consumer, 29.8% transaction costs and 26.3% lost to media productivity, and put working media at 45.1% in Q2 2026 (ExchangeWire, 16 September 2026). Adalytics' finding that one SSP took between 7% and 42% on the same site with the same buyer shows the tax is neither flat nor disclosed (ExchangeWire, 16 September 2026). The ExchangeWire piece itself avoids the phrase and describes the costs as fees "some visible on invoices and others embedded in transactions."

Standards bodies have begun to respond. IAB Tech Lab launched an Industry Council on programmatic transparency on 21 April 2026 (IAB Tech Lab, 21 April 2026) and released Programmatic Standard Practices v1 for public comment on 16 September 2026, with the stated aim of "reducing unnecessary transaction costs and increasing transparency" (IAB Tech Lab, 16 September 2026). SupplyChain v1.1 and the Deals API's curator field are the technical side of the same effort.

Example: on $1 million of spend at 45.1% working media, the ad tech tax in the broad sense is $549,000; in the narrow sense of fees alone, using the 2024 split, it is about $298,000, with the rest being waste the advertiser could have avoided with better inclusion lists.

Related: working media, take rate, SPO, DPO.

Source: No formal definition; ANA benchmarks and Adalytics findings via ExchangeWire (16 September 2026); IAB Tech Lab Programmatic Standard Practices v1 (16 September 2026).

1. ExchangeWire, 16 September 2026
2. IAB Tech Lab, 21 April 2026
3. IAB Tech Lab, 16 September 2026