Seedtag is an advertising technology company that sells media placements chosen by what a page, video or streaming programme is about rather than by who is looking at it. Founded in Madrid in 2014 by two former Google employees, Jorge Poyatos and Albert Nieto, it built a classification system that reads text, images and video, assigns meaning to the content, then decides which advertisement belongs beside it. It exists because the alternative method, profiling individuals through third-party cookies and mobile identifiers, has been degraded by browser policy, operating system controls and data protection law. Content-based targeting needs no identifier at all.

The business now spans three things usually kept separate: a targeting technology, a media operation, and an exchange. As of September 2026 it is headquartered in New York and Madrid, employs more than 700 people and is led by chief executive Brian Gleason, with Advent International holding the controlling investment.

How the classification and trading stack works

The technology layer is branded Liz, an in-house system the company dates to its founding decade. According to Seedtag, Liz processes unstructured data across text, metadata, images and video, combining natural language processing, deep learning and computer vision, and analyses content in more than ten languages. It draws on direct integrations with more than 30,000 publishers and broadcasters and reads over 60 million articles a day. Those figures are self-reported, and the publisher count has climbed from a stated 12,000 in mid-2025.

Classification runs in two directions. One seeks placements: a page about long-distance running is a candidate for a footwear campaign. The other avoids them, and the avoidance side is older. A 2022 upgrade to the computer vision component was described as detecting up to 38 categories of negative content, including nudity, drugs and violence, at the level of individual images rather than page text. The brand suitability explainer sets out why one engine serves both the advertiser buying recipe pages and the advertiser excluding tragedy coverage.

Since 2025 the output has been marketed as neuro-contextual advertising, a category the company named itself. The claim is that classification extends past topic to interest, emotion and intent, scoring pages on emotional tone as well as subject.

Trading sits on top. Seedtag operates on the sell side, so buyers reach its inventory through a demand-side platform rather than directly. It has been an exchange option in Display & Video 360 for years and appears in the standard supply chain plumbing: an exchange identifier matching the canonical domain of the selling system, seller identifiers published in a sellers.json file, and nodes appended to the SupplyChain object as a bid request travels. Filtering supply by seller identity uses the same fields, a capability Display & Video 360 charges 1.5% of media cost to use. Each impression is described in an OpenRTB bid request before anyone bids, and a contextual signal is only usable if it is attached at that point.

In April 2026 this was consolidated into NeuroX, an exchange that applies the Liz layer to every impression in the network before it is traded. Three activation routes were offered at launch: managed service, curated supply paths, and open marketplace buying inside existing DSPs. A self-serve curation tool for agencies followed in June 2026.

Origins and evolution

Seedtag began in a narrower niche. Its original product was in-image advertising, placing units inside editorial photographs, which made image recognition a founding competence rather than a later addition. Adara Ventures led an investor syndicate in 2016; a Series A of $5.2m closed in 2017.

Consolidation started in late 2020 with AtomikAD in Italy and Recognified in Germany. The French firm KMTX, previously Keymantics, followed in 2021. In September 2021 Oakley Capital led a $40m Series B, contributing $35m for a minority stake alongside Adara Ventures and All Iron Ventures. Disclosure accompanying that round put 2020 revenue at $50m, up 25% year on year, with $80m forecast for 2021.

The step change came in July 2022, when Advent International invested more than 250 million euros. Proceeds were earmarked for the contextual AI, US expansion and further acquisitions. All three followed. Contextual TV launched in the US in March 2024, combining automatic content recognition signals from streaming with open web contextual data. On June 3, 2024 the company acquired Beachfront, a New York sell-side platform specialising in connected television and streaming, adding roughly 30 staff and direct CTV supply; the price was not disclosed. JustEggs, a Sydney creative intelligence business founded in 2013, was acquired in July 2024, taking the company to a stated 17 markets.

Leadership changed on August 1, 2025, when Gleason, previously global chief revenue officer and president of retail media at Criteo and before that global chief executive of Xaxis, became chief executive. Poyatos moved to chief innovation officer and Nieto to strategic adviser, both remaining on the board.

Why it matters for marketers

The commercial case for content-based targeting rests on how much addressability has already gone. A contextual performance guide put identifier coverage gaps at 54% of mobile impressions and 36% of desktop impressions. Where there is no identifier, content is often the only signal left, which is why IAB Australia's video framework names Seedtagalongside Amazon, Google, Microsoft, Integral Ad Science, Zefr, Peer39, Proximic and Silverpush as contextual providers.

The second reason is structural. Decisioning has been migrating from the buy side to the sell side, and curation is the mechanism. A curated supply path packages audience, content signal and inventory into a deal a buyer activates from an existing seat, so a vendor that owns supply competes for a different budget line than one selling segments into someone else's platform. Match rate losses between platforms typically run between 40% and 70%, the figure anchoring the curation debate since 2024.

Seedtag also sits inside identity infrastructure it does not depend on, having been among eleven supply-side platforms that integrated the telco-backed identifier Utiq in January 2025 and remaining on the confirmed list when The Trade Desk adopted Utiq signals across EMEA in 2026.

Limitations and disputes

The neuroscience framing is the most contested part of the proposition. Evidence for it comes from a study run with Professor Moran Cerf of Columbia University, published on November 19, 2025, which used electroencephalography to compare neuro-contextual placements against standard IAB contextual and non-contextual advertisements. Reported results were 3.5 times higher neural engagement than non-contextual advertisements, a 30% lift over standard contextual, and a 26% increase in positive emotional response. The study was commissioned by the company, has not appeared in a peer-reviewed journal, and measures neural response rather than sales. Neural engagement is not a currency any buyer transacts on.

The category name carries the same problem. Neuro-contextual is not defined by IAB Tech Lab, the Media Rating Council or any standards body, so nothing external governs what qualifies. Buyers weighing it against verification vendors' contextual libraries, such as the page-level system Integral Ad Science documented in March 2026, have no shared taxonomy for the comparison.

Owning supply invites the criticism aimed at every intermediary. Jounce Media found the average real-time bidding publisher directly integrated with 24.5 sell-side platforms as of March 2025, with rebroadcasting paths accounting for 37% of display auctions, which cuts against treating presence in a bid stream as evidence of a distinct route. Research published by TripleLift in June 2026 found 60% of buyers did not know what they were paying for curation and 81% reported deal performance falling short. IAB Spain's supply-side guide reported that 90.3% of impressions concentrate on 3,000 sites while activated domains have more than doubled since 2023.

There is also a positioning tension. A company whose pitch is advertising without identifiers carries a telco-derived identifier on the supply side. Both positions can be commercially rational; they are not the same story.

Disambiguation

Contextual segment vendors. Peer39, Proximic, Zefr and Integral Ad Science classify content and sell the resulting segments into buying platforms. Seedtag classifies content and sells the media, making it a counterparty rather than only a data supplier.

In-image advertising. The format Seedtag started with and still sells. It describes a creative unit rendered inside an editorial photograph, not a company or a targeting method.

Contextual targeting and brand suitability. Both use the same classification. Targeting seeks content; suitability excludes it. Language targeting is narrower again, selecting by the language a reader is judged to understand rather than by subject.

NeuroX and neuro-contextual. The first is the exchange launched in April 2026. The second is the category label applied to the targeting method it carries.

Recent developments

Scale indicators have been visible in third-party data. DataBeat's programmatic report covering August 2026 placed Seedtag third in its Established seller tier at 169 net publisher line additions, behind Ozone and RISE.

The clearest recent signal is a renaming. Google is relabelling the exchange in Display & Video 360 reporting from Seedtag to Seedtag NeuroX on September 21, 2026, with exchange identifiers unchanged, as part of a fourteen-item platform roadmap. The unchanged identifier is the operative detail: blocklists, allowlists and supply path reports keyed to it keep working while dashboards show a new name. The same roadmap consolidates brand suitability controls into three inventory modes and ten content themes on October 1, 2026, removing category-level exclusions that some advertisers hold as contractual obligations and raising the value of vendor-side classification.

Executives have also been arguing the sell-side case in public. When Amazon introduced automatic deal selection for streaming television in May 2026, chief technology officer Kartal Goksel commented that deals going unused because buyers never found them had been an open secret in ad tech for years.

Timeline

  • 2014: Seedtag founded in Madrid by Jorge Poyatos and Albert Nieto, selling in-image advertising
  • 2016: Adara Ventures leads the first investor syndicate
  • 2017: Series A of $5.2m closes
  • Late 2020: AtomikAD in Italy and Recognified in Germany acquired; revenue reported at $50m for the year
  • 2021: KMTX, formerly Keymantics, acquired in France
  • September 14, 2021: $40m Series B led by Oakley Capital, which contributes $35m for a minority stake
  • July 27, 2022: Advent International invests more than 250 million euros
  • 2023: Market entries in India and Peru
  • March 2024: Contextual TV launched in the United States
  • June 3, 2024: Beachfront acquired, adding connected TV supply
  • July 2024: JustEggs acquired, taking the footprint to 17 markets
  • June 5, 2025: Neuro-contextual advertising launched as a category, with the Liz Agent built on retrieval-augmented generation
  • July 8, 2025: Brian Gleason named chief executive, effective August 1
  • November 19, 2025: EEG study with Professor Moran Cerf published
  • April 22, 2026: NeuroX exchange launched
  • June 2026: Self-serve curation platform released to agencies
  • September 21, 2026: Display & Video 360 renames the exchange Seedtag NeuroX, exchange identifiers unchanged

Summary

Who: Seedtag, founded by Jorge Poyatos and Albert Nieto, controlled by Advent International since 2022 and led by chief executive Brian Gleason since August 2025, with the founders serving as chief innovation officer and strategic adviser.

What: A contextual advertising company that classifies text, images and video through its Liz system and sells the resulting placements across the open web, online video and connected television, trading through the NeuroX exchange as well as managed service and curated deals.

When: Founded 2014; Series B September 2021; Advent investment July 2022; Beachfront acquired June 2024; neuro-contextual category launched June 2025; NeuroX exchange launched April 2026; Display & Video 360 rename September 21, 2026.

Where: Headquartered in New York and Madrid with roughly 700 staff across EMEA, Latin America, North America and Asia-Pacific, reaching a stated network of more than 30,000 publishers and broadcasters.

Why: Identifier-based targeting has lost coverage across mobile and desktop inventory, leaving content as the most widely available signal. Seedtag's response has been to move from selling a targeting technique to owning the supply path it runs on, which places its performance claims, its self-defined category and its fee structure under the same scrutiny applied to any other intermediary.