Bill Wise gave AdExchanger the cleanest version of the argument we are about to make against him. “There’s no other company, except for Google, that has everything in one place,” the Mediaocean co-founder told AdExchanger’s Allison Schiff the day he announced the Innovid acquisition in November 2024. “But what Google doesn’t have is neutrality and independence.” Read it twice. Wise was admitting Mediaocean had assembled a Google-equivalent stack. The defense was that Mediaocean’s stack would be neutral. We argue that defense has decayed. Fourteen months later, after a wave of full-stack ad-tech consolidations that finished or repositioned in the past eight weeks, “independent” no longer describes a different architecture. It describes a smaller walled garden, marketed as something else. Buyers should treat it accordingly.
The 2026 wave is the evidence. The Trade Desk launched the Ventura Ecosystem in late February, bundling OpenPath (supply path), UID2 and EUID (identity), OpenAds (ad serving), and OpenPass (authentication) under one vendor’s control. We covered the reframing in detail when the company abandoned its CTV-OS bid. Viant agreed in mid-April to absorb TVision Insights — the panel iSpot, VideoAmp, and Oracle Advertising had all rented from — for $40 million; our analysis at the time read the deal as the collapse of the neutral attention layer into a DSP. The Mediaocean–Innovid–Flashtalking platform closed in February 2025 and has had 14 months of operating life under the “independent omnichannel ad-tech platform” banner; the 2026 read is that the precedent is mature, not that the deal is fresh. And Amazon — already the reference template — wired Acxiom’s identity stack into its DSP on April 23 and donated its Dynamic Traffic Engine to the IAB Tech Lab the week before, where six days later the Tech Lab launched a Programmatic Governance Council with Amazon Ads as a founding member.
The five-layer audit defuses “we don’t own inventory”
The thing every full-stack walled garden owns is the same five layers: ad serving, creative personalization, identity, measurement, and supply path. Google does. Amazon does. The defense the consolidating “independents” reach for first is that they don’t own ad inventory, so the Google–Amazon comparison fails. That defense is true on one of the five axes and silent on the other four.
Score the 2026 cohort on the same rubric. Mediaocean owns ad serving and creative personalization through Innovid and Flashtalking, identity through Innovid’s graph and Flashtalking’s FTrack, measurement through TVSquared (acquired by Innovid in 2022), and the agency planning-and-clearing rail through Prisma. The Trade Desk owns ad serving through OpenAds, identity through UID2 and EUID, supply path through OpenPath, authentication through OpenPass, and measurement through Sincera (acquired June 2024) and Buy-Side Curation Marketplace primitives. Viant owns DSP impression delivery, creative through Adelphic, identity through Household ID, context through IRIS.TV (acquired November 2024), and now attention through TVision. Amazon owns Sizmek-derived ad serving and DCO (acquired May 2019), Acxiom-augmented identity, Marketing Cloud measurement, and the supply path through Amazon Publisher Cloud and Dynamic Traffic Engine.
Four of the five layers, in every case. The fifth — owned ad inventory — is real for Google and Amazon and absent for the others. That asymmetry is the substance of the “we are still independent” claim. Our argument is that one of five axes does not earn a different procurement category. Buyers can audit Viant’s measurement-loop conflict (Viant sells measurement of inventory bought through its DSP, with TVision now proprietary to Viant per PPC Land’s read of the deal, attribution Land’s). They can audit how OpenPath-routed supply gets weighted in TTD’s bid logic — which Cannonball Research estimates was about 10 percent of TTD revenue in Q3 fiscal 2025, and which Publicis told clients to avoid in March, per Adweek’s exclusive reporting, while Omnicom opened its own audit, per Ad Age. They can audit Mediaocean’s Prisma-as-clearing-rail position the same way they audit Google Ads’ billing-side leverage. The audits exist already. They do not require buyers to first agree the vendor is a walled garden; they require buyers to stop letting the “independent” label exempt the vendor from the audit.
The mirror is what convicts the consolidators. Tim Vanderhook told AdWeek the day Viant announced the TVision deal that “For too long, the biggest platforms have graded their own homework. This changes that.” The same release brought the panel three measurement vendors had been licensing from — under terms iSpot’s 2022 investment had structured as exclusive co-viewing-utilization rights across more than 900 streaming apps — inside Viant’s DSP. By Vanderhook’s own definition, Viant is now grading its own homework. Matthew Henick wrote in the Ventura Ecosystem launch that “Most TV operating systems today are owned by companies that are focused on their own agendas, rather than strengthening the broader marketplace.” He launched a Trade-Desk-controlled bundle of supply path, identity, ad serving, and authentication, then departed in early April — per Adweek’s exclusive — six weeks later. The Wise quote that opened this piece is the third instance of the same posture: a senior executive describing what makes the existing walled gardens problematic, while finishing the construction of one of his own.
What the smart pushback gets right
The strongest objection to the argument we are making is that Viant, Mediaocean, and TTD do not sell their own inventory. Henick made the cleanest version of it to AdExchanger in October 2025: “We will never have our own content service and we will never own any ad inventory.” That is a real distinction. Google routes Google Ads to YouTube; Amazon routes Amazon DSP to Prime Video and Amazon.com. The closed buy-side-to-owned-supply loop is the historical signature of a walled garden, and the consolidating independents do not have it. That argument is correct as far as it goes, and it goes further than critics like us tend to admit. Where it stops: ownership of the loop is not the only structural conflict that creates one. A DSP that owns its measurement primitive, an ad-server-plus-creative-platform that also owns the agency clearing rail, a supply-path layer that decides which inventory the bid sees — each is a structural conflict whether or not it ends in owned media. The 2026 audits Publicis, Omnicom, Dentsu, and WPP are running on TTD are the procurement system applying walled-garden-grade scrutiny to a vendor that calls itself independent, and the holdcos are doing it because the conflicts are real even without the inventory leg.
The second pushback is that buyers want one-throat-to-choke and full-stack pitches solve real procurement problems. We agree, fully. Frequency capping across screens, identity passthroughs, attribution stitching, billing reconciliation — every one of those is easier inside one vendor’s surface than across seven point solutions. We are not arguing against full-stack purchases. We are arguing against full-stack purchases that exempt themselves from full-stack audits because of the marketing word on the press release. The procurement category is “smaller-scale walled garden, with potentially better audit terms,” not “neutral independent.” The questions the ANA’s transparency benchmark work — which moved working-media reach from roughly 36 percent of every dollar entering a DSP in December 2023 to 43.9 percent in December 2024 — applies to DV360 and Amazon DSP equally, are the same questions buyers should apply to Viant, Mediaocean, and TTD. Log-level data access. Supply-path-fee disclosure. Made-for-advertising exposure. Identity-match-quality audit. Attribution-methodology disclosure.
The third pushback is that the IAB Tech Lab’s new transparency apparatus may genuinely fix the supply-path waste it is built to address. The Dynamic Traffic Engine, donated by Amazon and run in beta with OpenX and PubMatic since early 2025, addresses a bid-duplication cost the council’s buy-side co-chair Ben Hovaness pegged at one-sixth of programmatic ad-tech costs, per AdExchanger. We concede that the Tech Lab as an institution has produced real wins — OpenRTB, ads.txt, sellers.json, and the SupplyChain Object are buy-side transparency outputs the open programmatic stack genuinely depends on. But this council’s seating chart is the issue. Per Joe Mandese at MediaPost, the PGC has 13 founding members — three holdcos for the buy-side seat, eight publishers and SSPs for the sell-side, plus Amazon Ads and The Trade Desk — and zero direct advertisers. No P&G. No Unilever. No ANA. Mandese’s question is the load-bearing one: “Which raises an important question for the new council’s mandate: transparent for whom?” A standards body the consolidators sit on, with the SSPs that endorse the consolidators’ protocols, governing the auction the consolidators transact in, can produce useful technical specs and simultaneously fail to produce the buy-side auditability the “independence” pitch promises. Both can be true.
What the audit looks like in practice
The honest pitch from the consolidating independents would say: we are a smaller walled garden competing with the big ones. Here is what is auditable about us, here is what is not, and here are the conflicts of interest that come with the integration. None of the four 2026 vendors is making that pitch. Until they do, the procurement work falls to buyers.
Apply the same questions to a Trade Desk Ventura Ecosystem, a Mediaocean–Innovid–Flashtalking platform, a Viant–TVision–IRIS.TV stack, and an Amazon DSP–APC–DTE–Acxiom-via-Audience-Hub graph that you would apply to Google Ads, DV360, and Campaign Manager 360. Demand log-level data access on every layer of the stack, not just the demand side. Demand supply-path-fee disclosure measured the same way Publicis and Omnicom are measuring it on TTD. Demand attribution-methodology documentation that survives transfer to a third party. Demand identity-match-quality reporting that does not rest on the vendor’s own graph being the ground truth. Insist that DSP-owned attention measurement be evaluated against the same currency-certification rubric the Joint Industry Committee drafted in 2023 for independent vendors. Treat any “independent ad tech” line in a procurement deck as the marketing claim it has become; treat the audit as the procurement.
The May 11–14 NewFronts is the next test of whether anyone changes the questions. The May 7 Trade Desk Q1 print is the first quarter where the audits already running on TTD show up against numbers. We will know more by the summer. What we know now is that the four 2026 consolidations have done the same structural thing the consolidations they pitch against did, and that the word doing the work to make the procurement implication different is “independent.” That word is no longer load-bearing. The audit is.
