Learn & Understand

The Full Supply Chain Behind a Single Programmatic Ad Dollar

A simple two-party markup calculation - agency price versus underlying media cost - is a useful starting model, but a real programmatic transaction typically routes through several more intermediaries than just "agency" and "publisher," each taking a cut along the way.

The Real Chain of Intermediaries

A single programmatic ad impression commonly passes through a demand-side platform (DSP, representing the advertiser's buying interest), sometimes a separate agency trading desk managing that DSP relationship, various data and verification vendors (brand safety checks, viewability measurement, fraud detection), an ad exchange or supply-side platform (SSP, representing the publisher's selling interest), and finally the publisher itself. Each technology layer in this chain typically takes a fee or margin for the service it provides, meaning the gap between what an advertiser pays and what a publisher actually receives for the identical impression can be the accumulated result of several separate fees stacking together, not a single clean markup between two parties.

The ANA Study That Made This Visible Industry-Wide

The Association of National Advertisers (ANA) commissioned a landmark media transparency study, published in 2016, that examined actual programmatic transaction data across the supply chain and found that a substantial share of advertiser spend - commonly cited figures put it at roughly half, in the specific transactions studied - never reached the publisher at all, being absorbed instead by the various intermediary fees and margins along the way. This research was widely credited with accelerating industry-wide demand for genuine supply-path transparency, pushing advertisers to specifically ask for and negotiate visibility into exactly which intermediaries were taking a cut of their spend, rather than accepting an opaque total price with no visibility into how it was actually being distributed.

ads.txt and sellers.json: The Technical Tools Built in Response

Both tools emerged directly from the industry's post-2016 push toward supply-path transparency, giving advertisers and their agencies a standardized, machine-readable way to verify which intermediaries are legitimately authorized to sell a given publisher's inventory, and to trace how many distinct sellers sit between an advertiser's bid and the actual publisher - information that was largely invisible before these standards existed.

Why "Markup" Is Genuinely a More Complex Question Than a Single Percentage

A calculated markup percentage between a reported agency/platform price and an underlying media cost figure is a useful and legitimate starting metric, but in a real multi-party supply chain, that "underlying media cost" figure itself may already have several layers of intermediary fees baked into it before it ever reaches this calculation - meaning a genuinely complete picture of where an ad dollar goes typically requires supply-path mapping tools like ads.txt and sellers.json data, not a single markup calculation between two named parties alone.

Applying This When Evaluating Programmatic Spend Efficiency

Beyond calculating a simple markup figure, requesting supply-path transparency reporting from a programmatic partner - identifying every intermediary fee along the actual chain from advertiser spend to publisher payout - gives a materially more complete picture of where ad dollars are actually going than a two-party markup calculation alone can reveal, exactly the gap the ANA's research first brought to widespread industry attention.