Curation, in programmatic advertising, is the practice of assembling impressions from one or many publishers, attaching data to them, and selling the result as a single deal identifier that any demand-side platform (DSP) can bid on. The selection happens on the sell side, inside or alongside a supply-side platform (SSP), before the bid request is sent. The idea exists because the open auction hands buyers an unfiltered stream of requests and leaves them to do the sorting, while their own platforms can only evaluate a fraction of it. Germany's digital trade association BVDW, in a whitepaper published on 26 February 2026, defined curation as the targeted selection, combination and enrichment of inventory and data signals into packages aligned to specific campaign objectives.

How a curated deal is built

The starting material is ordinary supply. A publisher connects its sites, apps or streaming channels to an SSP and permits third parties to package that inventory. A curator then defines a package using targeting dimensions such as domain, app ID, geography, device, content category or audience segment, and the SSP issues a deal ID for it. The curator hands that ID to an agency or advertiser, who enters it into whichever DSP they use.

When a matching impression becomes available, the SSP inserts the deal into the bid request. Under OpenRTB 2.x, deals sit in the pmp object of each impression, and every deal carries its own id, bidfloor and auction type, alongside optional seat and advertiser domain allow-lists. A single request can carry several deals at once plus the open auction. According to Jounce Media's March 2025 analysis of 1.5 billion bid requests from 44 exchanges, reported by AdExchanger, the average request carried 3.5 deal IDs, and only 18.6% of bidding opportunities were pure open auction.

The curator's payment is usually built into the price. Google's Ad Manager documentation states that curation partners set a single fee for each data segment or package, and that Google deducts it from the bid price before the bid enters the auction. A curated package can also declare its own floor, which applies only where it is higher than the publisher's. Curators on Google's platform take part through a server-to-server interface called Real-time Curation, and must answer each segment request within 50 milliseconds. Google introduced the agency-facing version of this workflow on 4 November 2024, naming data partners including LiveRamp, and later renamed the publisher setting "Allow Inventory Curation" to "Allow Inventory Packaging" while widening identifier sharing from 23 August 2025.

Who does the curating

The role is open to almost anyone with data or a buying mandate. The BVDW paper names four archetypes: technology providers operating curation platforms, publishers packaging their own inventory, media buyers curating in self-service mode, and data providers selling curated deals through SSPs. In practice that list includes SSPs with their own products, specialist data companies such as Audigent, agency trading desks, and retailers or travel companies with first-party audiences. Buyers still choose the DSP, set the bid and control frequency. What moves is the decision about which impressions are worth seeing.

Origin and evolution

Packaged supply is older than the label. Private marketplaces, invitation-only auctions run on deal IDs, gave publishers a way to sell selected inventory to named buyers through the 2010s. OpenX has dated its own curation work to 2018, when it launched OpenAudience and an identity graph for activating partner data, according to the company's 2025 platform announcement.

The multi-seller form took shape around AppNexus technology. Dentsu Aegis Network and Xandr announced Dentsu Curate, a supply marketplace for Asia-Pacific built on Xandr's platform, on 16 September 2020. Xandr described 2020 as the foundational year for Xandr Curate, a self-serve tool for packaging inventory from multiple sellers with data into exchange-level deal IDs, and announced its commercial launch from Singapore in April 2021. A year later the company added an Inventory Library to its DSP for discovering curated deals across SSPs.

Standards bodies arrived late to the vocabulary. IAB Tech Lab chief executive Anthony Katsur argued in a November 2024 post that the organisation had already published the pieces: Seller-Defined Audiences, the content and audience taxonomies, the Data Transparency Standard and the OpenRTB SupplyChain object. Conceding weak adoption, he suggested, according to AdExchanger, that "we should rename this 'Curated Audiences'". PPC Land traced the frameworkto early 2023.

Commercial activity then accelerated. Microsoft opened its partner programme to curation technology providers on 27 February 2025, and less than three months later said it would close its Invest DSP on 28 February 2026 while keeping Monetize and Curate. OpenX made OpenXSelect generally available on 16 July 2025. Magnite folded discovery, packaging and activation into ClearLine on 1 October 2025. On 4 December 2025, IAB Tech Lab opened its Deals APIversion 1.0 for comment, adding a Curation object that names the curator's domain and classifies its fee as a percentage of spend, a flat fee, a CPM or none.

Why it matters to marketers

Curation relocates targeting decisions and the margin that comes with them. Sell-side platforms argue that data applied before the request preserves addressability. Equativ, which rebranded its curation environment Maestro in January 2025, put match rate losses between platforms at 40% to 70% in its own October 2024 analysis, a vendor figure that has since circulated widely. Filtering upstream also reduces request volume, which matters because DSPs throttle the queries per second they accept.

The shift has a structural edge. A curated deal is still a path through intermediaries; PPC Land's supply path explainerdescribes it as a route with an extra enrichment step rather than a shorter one. For advertisers, the practical question is which company chose the impressions, on what data, and at what price. For publishers, inclusion in popular packages now shapes revenue as much as open auction demand does.

Limitations and disputes

Fee visibility is the central complaint. Jounce Media's April 2025 benchmarking, as summarised by the publisher consultancy Playwire and by AdExchanger, found that about half of curated deal IDs carried no fee beyond the exchange's standard take. About 34% used a percentage markup with a median of 14%, some 10% charged a fixed CPM with a median of $0.48, and roughly 7% declared a static floor regardless of the impression, often implying margins above 50%. A fixed fee can distort: AdExchanger's example of a $0.25 fee on an impression clearing at $0.20 works out to 55% of the winning bid. Jounce founder Chris Kane said when the Deals API was released that buyers "should have basic line of sight into the companies that are packaging inventory".

Efficiency claims are also contested. According to Playwire's reading of Jounce's May 2025 report, curated deals showed reselling rates virtually identical to open auction inventory, and moving budget into them redistributed spend between publishers rather than adding to it. Deal hygiene is a further weakness. Magnite's Nick Allen said at the Deals API launch that "two-thirds of deals are configured with the desired supply, yet deliver no or very little revenue." The specification itself warns that deal terms sent through the API are not guaranteed to match the bid request.

The definition remains unsettled. At IAB Europe's Virtual Programmatic Day on 3 July 2025, panellists split on whether curation was new at all. Stephanie Briec of Comcast Advertising said broadcasters and streamers had "always been doing curation", while Microsoft's Matthew Adams called buyers leaning into curation "the real path forward". An audience member from an independent DSP asked whether it offered cover for culling suppliers.

Not the same as

Private marketplace. One seller, or a defined set, inviting named buyers into an auction. Curation uses the same deal mechanics but typically aggregates many sellers and is often run by a third party. Programmatic guaranteed deals differ again by fixing price and volume.

Supply path optimisation. A buy-side practice of choosing which routes to bid through and cutting redundant ones. Curation is a sell-side packaging step; the two can be combined but answer different questions.

DSP data targeting. Segments applied inside a buying platform, with itemised costs in the DSP's reports. In curation the same data is applied upstream and priced into the deal.

Content curation. The editorial sense, meaning human or algorithmic selection of articles, posts or videos for an audience. It shares the word and nothing else.

Recent developments

Retailers and platforms with first-party data have become curators in their own right. Expedia Group routed traveller data through Magnite's publisher relationships in a DSP-agnostic structure announced on 16 April 2026. On 27 April 2026, Roku introduced Roku Curate, pairing purchase data with its own streaming inventory, and Walmart Connect launched Connect Select with four supply partners. LinkedIn audiences now reach streaming inventory through deals built in Microsoft Curate, a May 2026 development. In August 2026, InMobi opened a direct line for agencies into its supply. Most recently, Magnite added 27 named data and publisher partners to its self-serve ClearLine Activate on 9 September 2026. Cost pressure has followed the growth: OpenX automated partner discounts for more than 80 curation and technology partners in September 2025, an admission that the layer's fees are now a negotiating line.

Timeline

  • 2018: OpenX launches OpenAudience, which it later cites as the start of its supply-side curation work
  • 16 September 2020: Dentsu Aegis Network and Xandr announce Dentsu Curate for Asia-Pacific
  • April 2021: Xandr announces the commercial launch of Xandr Curate from Singapore
  • June 2022: Xandr adds an Inventory Library for curated deals to its DSP
  • Early 2023: IAB Tech Lab's curation-relevant standards are in place, according to later accounts
  • November 2024: Anthony Katsur proposes renaming Seller-Defined Audiences as "Curated Audiences"
  • 4 November 2024: Google announces curation for agencies in Ad Manager
  • 27 February 2025: Microsoft Advertising opens its partner programme to curators
  • March 2025: Jounce Media analyses 1.5 billion bid requests and finds 18.6% pure open auction
  • 14 May 2025: Microsoft announces the closure of its Invest DSP
  • 3 July 2025: IAB Europe's Virtual Programmatic Day hosts a disputed panel on curation
  • 16 July 2025: OpenX makes OpenXSelect generally available
  • 23 August 2025: Google Ad Manager's revised curation settings and identifier sharing take effect
  • 1 October 2025: Magnite unifies curation and activation in ClearLine
  • 4 December 2025: IAB Tech Lab releases Deals API 1.0 for public comment, with a Curation object
  • 31 January 2026: The Deals API comment period closes
  • 26 February 2026: BVDW publishes its 12-page curation whitepaper
  • 28 February 2026: Microsoft Invest shuts down
  • 16 April 2026: Expedia Group and Magnite announce curated deals built on traveller data
  • 27 April 2026: Roku Curate and Walmart Connect's Connect Select launch
  • 9 September 2026: Magnite expands ClearLine Activate with 27 named partners

Summary

Who. Curators include SSPs, specialist data and curation companies, agency trading desks, publishers and data owners such as retailers and travel groups. Google, Magnite, OpenX, Equativ, Microsoft and Index Exchange operate the infrastructure. IAB Tech Lab and Germany's BVDW have supplied the definitions and standards.

What. Curation is the sell-side packaging of inventory and data into a deal ID that any DSP can bid on, with the curator's fee usually built into the deal price rather than itemised.

When. Multi-seller curation took commercial shape with Xandr's tools in 2020 and 2021, spread across major SSPs from November 2024, and gained a standard disclosure object in IAB Tech Lab's Deals API in December 2025.

Where. Inside or alongside SSPs and exchanges, upstream of the DSP, across web, app, audio and streaming television inventory worldwide.

Why. Buyers want fewer, better-qualified bid requests and data that survives the trip between platforms. Sellers and data owners want a share of the targeting margin. The dispute is over whether the resulting fees, supply choices and efficiency gains are visible enough to judge.