WPP Media allegedly generated $1 billion a year from undisclosed trading income

New Delhi: WPP was allegedly generating nearly $1 billion a year from undisclosed trading income, according to internal documents now part of a $100 million whistleblower lawsuit against WPP.

The allegations relate to GroupM, now known as WPP Media, which handles the company’s global media buying operations.

The $1 billion figure lies at the heart of the legal battle brought by former WPP executive Richard Foster. But another number in the filings may be even more unsettling for advertisers. 

According to WPP’s own data, 97.4% of its proprietary inventory was not being used by its largest clients. Google, its biggest US client with $2.3 billion in annual billings, used less than 1% of the inventory its spending helped create.

The lawsuit, filed in New York State Supreme Court, accuses WPP of building a hidden profit engine inside its media trading operations. Foster, who spent 17 years at the agency and most recently served as global CEO of Motion Content Group, claims the company retained rebates and trading benefits that should have flowed back to advertisers.

At its peak, WPP controlled roughly $60 billion in annual client advertising spend. That scale gave it huge leverage with global media platforms and broadcasters. By aggregating client budgets, the agency could hit spending thresholds that triggered cash rebates or discounted inventory from media owners.

According to the complaint, instead of returning the full value of those rebates to clients, WPP classified part of the inventory as proprietary media. It then resold that inventory to advertisers through opt-in arrangements and recorded the margin as non product related income.

Internal documents referenced in court show that non product related income, which includes rebates, services and purchase risk inventory, was approaching $1 billion annually. The same documents set a 15% year on year growth target for that income stream.

The scale of WPP’s platform relationships in 2023 underlines the leverage at play. Globally, the agency directed $9.4 billion in spend to Google, $3.7 billion to Meta, and $1.1 billion each to Amazon, TikTok and The Trade Desk. 

In the United States, Google alone accounted for $4.9 billion in spend, followed by $1.4 billion to Meta and hundreds of millions to major television networks including Disney and NBCU.

Yet the internal data shows that the largest clients whose budgets enabled those deals were barely using the proprietary inventory generated.

Among WPP’s top 30 US billing clients, representing $13.5 billion in total billings, only 5% of eligible spend was routed through proprietary deals. That means most of the inventory generated through aggregated budgets was not deployed by those advertisers.

The number becomes more stark when viewed in terms of unused supply. Of the proprietary inventory linked to the top 30 clients, 97.4% went unused. Among the top 10 clients, representing $8.5 billion in billings, 91.9% of proprietary inventory was not utilized. 

Google, the single largest US client at $2.3 billion in annual billings, used just 0.51% of available proprietary inventory. In effect, nearly all of it went unused.

Foster alleges he flagged these concerns internally in a 36 page report titled Project Claridges, submitted in December 2024 to then incoming WPP CEO Brian Lesser.

The report included data on opt in rates, platform spend and income targets. It also proposed restructuring WPP’s entertainment investments into a new consolidated division.

According to the complaint, Lesser acknowledged the concerns and said he would review them. Foster claims the unedited report was later shared with senior executives he had criticized. His division was subsequently placed under new oversight. Six months later, in July 2025, he was terminated during a broader restructuring.

WPP has denied the allegations and filed a motion to dismiss the case. The company argues that the report did not identify illegal conduct and was primarily a business proposal tied to Foster’s own ambitions.