Programmatic's Middle — What the Ad-Tech Layer Keeps Before the Publisher Sees Anything

What the Chain Actually Looks Like

When an advertiser commits a budget to programmatic advertising — the automated, auction-based buying and selling of digital ad inventory — the money does not travel in a straight line to the site that shows the ad. It passes through a stack of intermediaries: demand-side platforms (DSPs) through which advertisers buy impressions, supply-side platforms (SSPs) through which publishers make inventory available, ad exchanges that match the two, and a further layer of data brokers, verification vendors and ad-tech infrastructure providers that attach fees at each junction. The take rate — the share of gross transaction value retained by this middle layer before anything reaches the publisher — is the figure the industry has historically been reluctant to state plainly.

The clearest attempt to measure it came from the ISBA, the UK trade body representing advertisers, working with PricewaterhouseCoopers and the research firm Ebiquity. Their 2020 programmatic supply chain transparency study tracked £2.6 million in advertiser spending across more than 267 million impressions, matching transaction records from fifteen major advertisers to records from twelve publishers. The headline finding: publishers received 51 pence of every pound the advertiser spent. The ad-tech layer claimed 49 pence, roughly a third of which — 15 pence in the pound — could not be attributed to any identified vendor at all. The study called this "unknown delta."

That unknown delta was not an accounting error. It reflected the structural opacity of a supply chain where individual fees are often contractually confidential, auction dynamics are not fully disclosed to either advertiser or publisher, and the number of hops between a DSP bid and an SSP response can vary impression by impression. Fifteen percent of total advertiser spend went somewhere that a coordinated audit, backed by the largest advertisers and publishers willing to open their books, could not identify.

The 2023 Update, and What It Found

ISBA repeated and extended the exercise three years later. The 2023 programmatic supply chain transparency study, again produced with PwC and Ebiquity, drew on a larger dataset — around 21 billion impressions from fourteen advertisers and 48 publishers — and applied a methodology designed to reduce the matching gap that had limited the 2020 work.

The headline publisher-revenue share improved modestly. Publishers received approximately 57 pence in the pound by 2023, compared with 51 pence in 2020. The unknown delta shrank to around 3 percent of spend. Those movements are real, and the industry pointed to them as evidence that pressure from the original report, combined with adoption of protocols like sellers.json and buyers.json — machine-readable files that identify authorised participants in an auction chain — had produced some transparency progress.

What the improvement does not change is the underlying arithmetic. Even at the 2023 figure, advertisers' demand-side costs and publishers' supply-side deductions together consumed 43 pence in every pound before a publisher received its share. The studies do not decompose every fee category in public-facing detail, but the broad structure is: DSP fees typically quoted in the range of 10–15 percent of media spend, SSP fees in a similar range, with additional charges for data, brand safety verification and ad serving sitting on top. A campaign running through multiple SSPs — which is common, as publishers frequently list inventory across several platforms simultaneously — accumulates fees at each node.

The Interactive Advertising Bureau has maintained its Transparency and Consent Framework as a mechanism for disclosing data-processing purposes to users, but the IAB's framework addresses consent rather than fee disclosure; it does not require participating vendors to publish their take rates publicly. The distinction matters: a publisher can be listed as a compliant participant in an IAB-governed auction while the fees deducted from its revenue remain contractually confidential.

Regulatory Attention and What Has Been Named

The ISBA studies are industry-commissioned research, not regulatory filings. No enforcement action equivalent to the Federal Trade Commission actions brought against MOBE, Digital Altitude or similar schemes has been brought specifically against programmatic take rates in the United States. The FTC under Lina Khan did, however, expand its scrutiny of ad-tech concentration, and in January 2023 the Department of Justice filed an antitrust suit against Google's ad-tech stack — its publisher ad server, ad exchange, and advertiser buying tools — alleging that the combination of those products allowed Google to manipulate auction outcomes in its own favour. That case proceeded through pre-trial stages with a trial date set for 2024.

The DOJ complaint alleged specific practices: header-bidding suppression, in which Google's tools were alleged to have disadvantaged the open-header bidding mechanism that publishers had adopted partly to escape Google's pricing; and a practice internally referred to as "Project Jedi Blue," a claimed agreement with Facebook's advertising arm to reduce competitive pressure on Google's exchange. The substance of those allegations reflects the structural problem the ISBA studies identified from the buy side: when the same company operates the DSP, the exchange and the publisher ad server, the conflict of interest embedded in the middle of the chain is not visible in any single fee disclosure.

In the United Kingdom, the Competition and Markets Authority concluded a market study into online platforms and digital advertising in 2020, finding that Google's vertical integration in ad tech created barriers to entry and distorted competition. The CMA's 2020 study recommended that the government establish a new regulatory regime for digital platforms, including a dedicated body to oversee it, rather than relying on conventional competition enforcement alone.

What the Published Numbers Mean for Publishers

For a publisher running display advertising through the open programmatic market — as distinct from a direct-sold deal or a private marketplace arrangement — the ISBA figures translate into a structural reality: the effective CPM a publisher receives is a fraction of the CPM an advertiser reports paying. A campaign bought at a £5 CPM at the advertiser's desk does not produce £5 for every thousand impressions the publisher serves. After DSP fees, SSP fees and any unattributed deductions, the publisher's net CPM may be closer to £2.85 at the 2023 ratio, and closer to £2.55 at the 2020 ratio. Publishers typically see only the net figure; the gross is reported on the advertiser's invoice.

That gap is the operational meaning of take rate in programmatic. The ISBA studies are the most granular published measurement of its size; the CMA and DOJ proceedings are the most significant public-record examinations of whether that structure is legally sustainable. Neither inquiry has concluded that the fees are fraudulent. Both have concluded they are large, opaque, and concentrated.