Several U.S. media buyers explained that, following investigations into the overall cost of the product to their clients, they had pulled or paused investment from OpenPath.

Launched in 2022, The Trade Desk pitched OpenPath as a cleaner, more direct programmatic pipeline for publishers and advertisers. It’s used to directly connect advertisers with thousands of publishers from A+E Networks to Encyclopedia Britannica, including those offering in-demand CTV inventory. At the time, some saw it as just another way for the company to control the flow of ad dollars.

A spokesperson for The Trade Desk described OpenPath as “both a canary in the coalmine and a stalking horse. As a canary in the coalmine, OpenPath provides advertisers with essential signals on supply chain dynamics that they can apply across everything they do. As a stalking horse, it pushes all of us to implement ways we can improve those supply chain dynamics, so advertisers and publishers can make the most of every advertising dollar.”

On paper, the product is used without charge by advertisers and agencies (who still pay an assortment of platform and “tech” fees to The Trade Desk). Publishers using OpenPath to sell their ad space pay a fee to the company based on a percentage of advertiser spend, typically around 5%.

That’s a problem for media agencies — which are ultimately hired to get clients the best possible price on advertising inventory — because the prices they see could be variously affected by publishers raising floor prices, demand from other advertisers or inclusive of The Trade Desk’s take rate.

“There’s not a ton of visibility,” said one indie agency buyer, who exchanged anonymity for candor. After testing the use of OpenPath for the first time earlier this year, they said their agency had sworn off its use because of the lack of clarity over cost.

Another media exec at a large agency holding company — speaking anonymously to protect commercial relationships — said their firm had stopped spending via OpenPath altogether since autumn. Media agencies often devote as much as 10 to 20% of the spend they invest through The Trade Desk to OpenPath.

“As an organization, we have significantly deprioritized OpenPath as a supply path,” they said, without providing financial specifics. The company hadn’t pulled investment from The Trade Desk overall — but until more clarity on OpenPath’s costs became available, the buyer said it was off the table as a supply path.

The point of contention isn’t the cost itself, explained the anonymous holding company exec. Their own pricing estimates suggested OpenPath’s indirect cost was competitive, relative to its supply-side platform (SSP) peers. The issue is the lack of certainty: if the agency couldn’t look its clients in the eyes and explain to them with total confidence how much they were paying, and what exactly they were paying for, then it followed they’d have to step away from the product until further notice, they said.

Other execs have voiced similar frustrations in recent weeks. “We have to be transparent upstream for the way we run media,” said one buyer, speaking under Chatham House Rules during Digiday’s recent Programmatic Marketing Summit. The exec said that, after investigating the cost of media inventory bought via OpenPath with a direct to publisher transaction, they estimated The Trade Desk had applied a premium between 10 to 15% on transactions. As a consequence, they said their agency had reduced spending on The Trade Desk’s DSP overall.

Another independent media agency executive, who exchanged anonymity for candor, told Digiday they expected to review OpenPath costs in the new year.

“It is absolutely something that we’ll look at,” they said. “If you think about the history of the programmatic supply path, there’s been grasping hands everywhere… There’s money to be made in the path.”

A more cynical reading, shared by some ad tech experts, is that OpenPath’s appeal to “clean” supply also strips agencies of one of programmatic’s longstanding pressure valves: no ad tech intermediaries means no post-auction givebacks, meaning agencies aren’t able to protect margins on the back of programmatic buys.

Not every agency finds this state of affairs so problematic. “My goal is always to try to get the most direct path [with the] fewest number of hops… to the best inventory and platforms,” said Stephani Estes, chief media officer at The Shipyard, an agency which currently uses OpenPath.

Tessa Ohlendorf, president North America, Coegi, told Digiday she expected the agency’s investment on OpenPath to increase in tandem with its overall Trade Desk spend. “We’re not seeing any negative results coming from OpenPath,’ she said.

The Trade Desk’s latest earnings would appear to back that up. Q3 revenue rose 18% year on year to $739 million, aided by OpenPath growth of “many hundreds of percentage points,” according to CEO Jeff Green.

“Everything we do that interacts with the supply side, such as OpenPath and OpenAds, is intended to drive better signal and a more transparent marketplace for our advertiser and agency clients,” he told analysts in November.

The company has indicated that it will continue to develop OpenPath in 2026. “OpenPath has been very successful in pushing the entire ecosystem toward healthier supply chain dynamics. We will continue to iterate OpenPath with our ecosystem partners as they embrace it to drive better performance and outcomes,” the company’s spokesperson told Digiday.

What those iterations involve – and whether they will satisfy the firm’s demand-side skeptics – remains to be seen. Despite signs that its reps have been attempting to mend fraying ties between the company and media agencies, following arguments over reseller definitions and over the roll-out of its Kokai tool, it’s clear that practitioners maintain a wary stance toward The Trade Desk.