SSP-Native Audience Marketplaces: How Publishers Monetize Addressability Without Third-Party IDs
The third-party cookie era has taken its curtain call, and mobile ad IDs are in flux. Yet the most interesting story in addressability is not only on the buy side. It is on the supply side, where SSP-native audience marketplaces are becoming the operating system for privacy-safe monetization. These marketplaces turn what publishers already own — first-party data, contextual understanding, content taxonomies, and consent — into portable supply-side signals that buyers can trust and activate at scale. The goal is simple. Preserve and even improve audience precision without relying on third-party IDs. This thought piece explains how SSP-native audience marketplaces work, what good looks like, and how supply platforms and publishers can ship measurable revenue outcomes without violating privacy or overcomplicating operations. It covers web, mobile app, and CTV patterns, implementation examples, and a pragmatic roadmap. It also includes references to relevant standards and platform documentation where appropriate :cite[ekx,ctt,a41,dse,as1].
What Is an SSP-Native Audience Marketplace
An SSP-native audience marketplace is a supply-controlled environment that packages publisher signals into buyable audience products. It blends first-party cohorts, contextual labels, and standardized taxonomies into curated inventory that buyers can transact through PMPs, curated deals, or on-object signals in OpenRTB. The key difference from legacy data marketplaces is ownership and proximity. The signals originate at the source, are normalized by the SSP, and flow with the impression in a privacy-compliant way. This reduces data leakage and improves match rates. Core components typically include:
- Signal normalization: Align publisher first-party data to shared taxonomies like IAB Tech Lab’s audience and content taxonomies and map them into OpenRTB-compatible structures :cite[duj,ctt].
- Consent enforcement: Respect user choices via frameworks like IAB Tech Lab’s Global Privacy Platform, then gate signal activation accordingly :cite[bfd].
- Deal packaging: Turn cohorts and contexts into deals using PMPs, curated marketplaces, or dynamic deal construction at request time.
- Buyer activation: Make segments discoverable, forecastable, and plannable. Connect to buyer tools and enable test-and-learn.
- Measurement: Provide spend, reach, frequency, and outcome analytics that work in an ID-light environment.
Why Now
Three forces have converged:
- Privacy and platform changes: Third-party cookies are deprecating in Chrome and already constrained in other browsers. Mobile ad identifiers face consent friction. Addressability must be built on first-party and contextual data.
- Buyer SPO and signal trust: Buyers increasingly prefer inventory paths with clear provenance, fewer hops, and reliable on-object signals. Sell-side assembled audience signals with shared standards are easier to verify and scale.
- CTV’s rise: CTV has limited third-party identifiers and thrives on publisher and app-level context. Supply-led curation and app-ads.txt/sellers.json enforcement promote trust and transactable segments :cite[as1,a9i].
The Building Blocks of Supply-Led Addressability
Modern SSP-native audience marketplaces assemble multiple signal types and standards that work together.
1) First-Party Audiences at the Edge
Publishers capture authenticated profiles, declared interests, page interactions, and subscription events. These are transformed into cohorts rather than exposed as raw identifiers. Common patterns:
- Hashed ID spaces: Salting and hashing publisher IDs for on-platform analytics while avoiding re-identification risks.
- Household or account cohorts: Group-level audiences for CTV where user-level IDs may be unavailable.
- Lifecycle segments: New visitor, returning reader, subscriber, churn risk, high-intent browser.
The marketplace maps these to standard taxonomies so downstream systems can interpret them consistently :cite[duj,ctt].
2) Seller Defined Audiences and Taxonomies
Seller Defined Audiences (now being unified under Tech Lab’s curation efforts) provide a standard way for publishers and sellers to label audiences and communicate them in the bidstream without leaking raw user-level data :cite[ekx,aqj,cvs]. With SDA, a seller declares segment metadata in OpenRTB via user.data structures aligned to a taxonomy. This makes cohorts portable across publishers, while maintaining source ownership and transparency :cite[duj].
3) Contextual Signals at Scale
Contextual has matured beyond keywords. Publishers can supply content category, topic vectors, sentiment, and media-level signals like placement quality and page recency. Contextual complements cohorts and often performs strongly in privacy-constrained environments.
4) Consent and Privacy Signals
The Global Privacy Platform (GPP) consolidates jurisdiction-specific consent strings into a single framework. SSPs should ingest and enforce GPP signals for web and app flows. Cleanly separating consent capture, compliance logic, and activation reduces risk and speeds iteration :cite[bfd].
5) Publisher Provided Signals and PPID in Google Ad Manager
Within GAM-controlled supply, Publisher Provided Signals (PPS) enable publishers to package audience and contextual signals that buyers can receive programmatically in Authorized Buyers and DV360. Publisher Provided Identifiers (PPID) help with frequency and reach within GAM’s walls, while PPS exposes taxonomy-aligned labels :cite[a41,ajm,a18].
6) CTV App-Ads.txt and Sellers.json
Trust in CTV starts with inventory provenance. App-ads.txt for CTV app stores and sellers.json adoption improves transparency and reduces spoofing. For a marketplace, baking provenance checks into discovery and deal packaging is essential :cite[as1,a9i,enj].
Architecture Blueprint for an SSP-Native Audience Marketplace
Below is a practical architecture that balances performance, privacy, and operational simplicity.
Data Ingestion and Normalization
- Inputs: Publisher CRM cohorts, on-site events, content metadata, SDK signals for apps, ACR or channel metadata for CTV, and consent strings.
- Pipelines: Stream ingestion for time-sensitive signals, batch for historical enrichment, and a privacy layer that strips or hashes sensitive attributes before downstream activation.
- Mapping: Align all segment IDs to IAB audience and content taxonomies, with a clear provider naming convention required by SDA :cite[duj,ekx].
Identity and Governance
- Identity abstraction: No raw emails or device IDs in the bidstream. Use on-platform keys and cohort IDs with short TTLs.
- Consent enforcement: Evaluate GPP state per request; if unavailable or negative, serve contextual-only packages and suppress audience signals :cite[bfd].
- Data retention: Keep cohort membership TTLs conservative. Recompute often to avoid stale targeting.
Segment Catalog and Deal Builder
- Catalog: A searchable catalog of segments with definitions, provenance, population, and overlap estimates.
- Curated deal builder: Pack segments plus placement-level rules into deal IDs for rapid activation in DSPs. Provide forecasting APIs to estimate spend capacity.
- Taxonomy translations: Maintain mappings to buyer-side taxonomies when necessary, but keep source of truth in IAB standards where possible :cite[duj].
Activation and Delivery
- OpenRTB signaling: Populate user.data with SDA-aligned segments when consented. For GAM-based supply, also send Publisher Provided Signals :cite[a41,ctt].
- CTV enablement: Use app-ads.txt and sellers.json validation preflight. Build verticalized CTV packages like news live, sports highlights, or premium episodic :cite[as1].
- PMPs and curated marketplaces: Surface inventory and audiences to demand via deal IDs and allow on-the-fly curation for SPO-compliant paths.
Measurement and Reporting
- Lift-friendly reporting: Provide randomized test splits and eligibility flags so buyers can run incrementality tests without third-party IDs.
- Outcome templates: Offer templates for CTR, CVR where available, and post-campaign clean room workflows for conversions or reach reconciliation :cite[dse].
- Transparency: Break out performance by segment, context, and domain/app to guide optimization.
Implementation Examples
Below are practical examples that teams can adapt. These are illustrative and must be validated in your environment and with your partners’ requirements.
A) Prebid First-Party Data with ORTB2
Prebid supports first-party data in ortb2 fields which can carry taxonomy-aligned segments. This is one way to operationalize SDA-like signals client side or server side :cite[ctt,as7].
// Prebid.js configuration example for first-party data and audience taxonomy alignment
pbjs.setConfig({
ortb2: {
site: {
domain: "examplepublisher.com",
page: "https://www.examplepublisher.com/tech/top-laptops-2025",
content: {
// IAB Content Taxonomy category IDs
// Example only - use proper taxonomy IDs
cat: ["IAB1-6", "IAB19-11"],
keywords: "laptops,ultrabook,windows"
}
},
user: {
// Seller Defined Audiences-style data block
data: [{
name: "examplepublisher.com", // SDA provider
ext: { taxonomy: "IAB_AUDIENCE_TAXONOMY_V1" },
segment: [
{ id: "tech_intenders", name: "Tech Intenders", ext: { ttl: 7 } },
{ id: "high_value_subscriber", name: "High Value Subscriber", ext: { ttl: 30 } }
]
}]
},
regs: {
ext: {
gpp: "<GPP_STRING>", // Populate with your consent string
gpp_sid: [7, 8] // Example section IDs
}
},
device: {
dnt: 0
}
}
});
Server-side, Prebid Server supports similar first-party data propagation and SDA handling :cite[as7].
B) OpenRTB Bid Request Snippet with SDA
Below is a simplified OpenRTB 2.x user.data example with SDA-style segments and consent context. Replace values with your taxonomy and compliance state.
{
"id": "req-123",
"imp": [{
"id": "1",
"banner": { "w": 300, "h": 250 },
"pmp": {
"private_auction": 1,
"deals": [{
"id": "deal_sda_tech_intenders_q1",
"bidfloor": 1.5,
"at": 2
}]
}
}],
"site": {
"domain": "examplepublisher.com",
"page": "https://www.examplepublisher.com/tech/top-laptops-2025",
"content": {
"cat": ["IAB1-6", "IAB19-11"],
"title": "Top Laptops of 2025"
}
},
"user": {
"id": "anon-xyz",
"data": [{
"name": "examplepublisher.com",
"ext": { "taxonomy": "IAB_AUDIENCE_TAXONOMY_V1" },
"segment": [
{ "id": "tech_intenders", "name": "Tech Intenders", "ext": { "derivation": "onsite_intent_v2" } },
{ "id": "subscriber", "name": "Subscriber", "ext": { "tier": "gold" } }
]
}]
},
"regs": {
"ext": {
"gpp": "<GPP_STRING>",
"gpp_sid": [7, 8]
}
}
}
The user.id is a publisher-scoped pseudonymous value. Audience segments are attached as cohort labels rather than user-level identifiers, upholding privacy-by-design.
C) GAM Publisher Provided Signals (PPS)
Within Google Ad Manager, PPS lets you pass structured audience and contextual data to allowed buyers. Below is a conceptual GPT snippet to attach PPS labels on page load :cite[c5u,a41,a18].
<script async src="https://securepubads.g.doubleclick.net/tag/js/gpt.js"></script>
<script>
window.googletag = window.googletag || { cmd: [] };
googletag.cmd.push(function() {
// Example PPS config object
const pps = {
contextual_signals: {
content_category: ["IAB1-6", "IAB19-11"],
keywords: ["laptops", "ultrabook", "windows"]
},
audience_signals: {
// Use your GAM-approved taxonomies and labels
segments: ["tech_intenders", "subscriber_gold"]
}
};
// Apply PPS to the ad service
googletag.pubads().setPublisherProvidedSignals(pps);
// Define and display slots
googletag.defineSlot('/1234567/tech_section_top', [300, 250], 'div-gpt-ad-12345-0').addService(googletag.pubads());
googletag.enableServices();
});
</script>
<div id="div-gpt-ad-12345-0"></div>
Check your GAM account for PPS availability and the exact schema for your network. PPS is typically gated and requires policy compliance :cite[a41,ajm].
D) SQL-like Cohort Construction
For large publishers and SSP data teams, cohort construction often starts with simple eligibility rules. You can express these with transformations in your data platform.
-- Pseudocode for a weekly refreshed "Tech Intenders" cohort
CREATE OR REPLACE TABLE cohorts.tech_intenders AS
SELECT
user_key, -- publisher-scoped key
CURRENT_DATE AS as_of_date
FROM
events.pageviews
WHERE
page_category IN ('laptops', 'pc-hardware', 'reviews')
AND event_date >= CURRENT_DATE - INTERVAL '14' DAY
GROUP BY user_key
HAVING COUNT(*) >= 3;
The output feeds your audience catalog and powers both SDA mappings and PPS labels. Always ensure consent and jurisdiction logic are applied before activation.
How Marketplaces Package and Price Addressability
SSP-native audience marketplaces thrive when they are easy to buy, forecastable, and consistent across surfaces.
- Package design: Build a pyramid of packages. At the base, contextual-only packages. In the middle, first-party cohorts by vertical. At the top, high-intent micro-cohorts for performance buyers.
- Forecasting discipline: Publish weekly capacity and reach estimates per geography and device class. Expose a planning API that buyers can call before they request a deal.
- Pricing: Charge via bid floors in deals, segment access fees, or curated marketplace fees. Keep the take rate transparent to avoid buyer fatigue.
- Outcome commitments: Offer learning agendas and incrementality testing plans rather than hard guarantees. Be clear about limitations in ID-light measurement.
CTV Use Cases Without Third-Party IDs
CTV addressability relies heavily on publisher and app-level signals. Marketplaces can deliver:
- Content-centric packages: Genre, rating, network, daypart, and live vs on-demand classifications.
- Household-level cohorts: Based on subscription level, content affinity, and viewing cadence. All privacy-compliant and aggregated.
- Channel and device quality: Verified app-ads.txt sellers, authorized resellers, and certified measurement partners :cite[as1].
- Retail and commerce tie-ins: Clean room activations for outcome measurement at the household level without exposing raw IDs :cite[dse].
What matters most in CTV is provenance and quality. Use app-ads.txt, sellers.json checks, and clear inventory descriptions. Offer curated deals by network or content cluster. Provide forecasting by ad pod position and genre.
Measurement and Optimization in an ID-Light World
Measurement does not end with third-party IDs. It changes shape.
- Clean rooms for reconciliation: When buyers have conversion or CRM data, use clean room workflows to compute reach and outcomes while keeping both sides’ raw data private :cite[dse].
- Geo and time-based experiments: Where clean rooms are not available, use geography or time-slicing to estimate lift with control and exposed cells.
- Modeled attribution: Blend click and exposure data with econometric methods. Be honest about confidence intervals and data gaps.
- Creative and context testing: In ID-light environments, context and creative matter even more. Embed testing constructs in packages.
Common Pitfalls and How to Avoid Them
SSP-native marketplaces can stall when teams overlook the basics.
- Over-segmentation: Too many micro-cohorts hurt scale and planning. Start with broader segments and allow buyers to request refinements.
- Taxonomy drift: If each publisher uses different labels, buyers cannot plan. Enforce IAB taxonomies and keep a translation layer for edge cases :cite[duj].
- Opaque fees: Hidden markups erode trust. Publish fee structures for curated deals.
- Consent blind spots: Respect GPP signals end to end. Fail closed when consent is ambiguous and provide contextual fallbacks :cite[bfd].
- CTV provenance gaps: Do not package inventory without app-ads.txt and sellers.json checks. Ensure resellers map to authorized sellers :cite[as1,a9i].
How Publishers Should Prepare
Even before an SSP marketplace opportunity arises, publishers can set themselves up for sustained success.
- Strengthen first-party capture: Grow authenticated audiences, enrich content metadata, and standardize event taxonomies.
- Adopt SDA-style structures: Maintain a catalog of cohorts mapped to IAB audience taxonomy with clear derivation logic and TTLs :cite[ekx,duj].
- Implement PPS in GAM: Where relevant, enable PPS and PPIDs to improve yield in GAM-controlled demand :cite[a41,ajm].
- Harden CTV transparency: Deploy app-ads.txt, keep it fresh, and validate sellers.json relationships with partners :cite[as1,a9i].
- Plan for clean room workflows: Identify strategic buyers who can support clean room measurement and define the minimum viable match space :cite[dse].
How SSPs Can Differentiate Their Audience Marketplaces
The most effective SSP-native marketplaces share a few attributes.
- Standards-first: Lean on SDA, IAB taxonomies, GPP, and OpenRTB structures. Keep proprietary innovation at the orchestration layer, not the payload :cite[ekx,duj,bfd].
- Segment quality scoring: Rate segments by freshness, consent coverage, observed performance, and stability. Expose scores to buyers.
- Discovery and forecasting UX: Treat the catalog like a storefront. Natural language search, overlap insights, and spend capacity indicators.
- Buyer integrations: Make activation turnkey in major DSPs using deal IDs and curated marketplace connectors. Provide troubleshooting playbooks.
- Privacy proofs: Maintain auditable logs showing how consent was evaluated and which signals were suppressed per request.
The Role of Red Volcano
Red Volcano focuses on supply-side intelligence. Our tools help SSPs and publishers build and scale audience marketplaces with confidence.
- Publisher discovery and tech stack mapping: Identify supply with strong first-party data programs, PPS adoption, and Prebid readiness. Pinpoint who is SDA-capable and who needs uplift.
- ads.txt, app-ads.txt, sellers.json monitoring: Validate CTV and app supply provenance at scale. Flag unauthorized resellers and outdated entries that can derail curated deals.
- SDK and mobile app intelligence: Surface which SDKs can supply audience and contextual signals, and where privacy-safe enrichment is most viable.
- CTV data platform: Map app stores, bundles, developer sites, and app-ads.txt coverage to guide packaging for CTV marketplaces.
- Sales outreach services: Equip partner teams with evidence and talking points to onboard publishers into SDA and PPS workflows.
By lighting up supply readiness and gaps, Red Volcano de-risks marketplace rollouts and accelerates revenue from privacy-safe audiences.
A Practical Rollout Plan
Here is a pragmatic plan SSPs and publishers can use to stand up a marketplace within two quarters.
Phase 1: Foundations and Pilots
- Publisher cohort audit: Inventory available cohorts, TTLs, derivation, and consent coverage. Map to IAB taxonomy.
- Consent enforcement path: Implement GPP parsing, default-to-contextual rules, and logging for audits :cite[bfd].
- Marketplace MVP: Build 10 to 15 high-value segments across 3 verticals. Package as PMPs with clear naming and minimum scale thresholds.
- Buyer beta: Onboard 5 to 10 buyer teams. Agree on learning agendas and measurement methods.
Phase 2: Scale and Optimization
- Forecasting APIs: Publish capacity and reach estimates with day-level freshness.
- CTV expansion: Add 3 to 5 CTV content-centric packages once app-ads.txt and sellers.json checks are complete :cite[as1,a9i].
- Segment scoring: Launch freshness and performance scores. Deprecate low-quality cohorts.
- Clean room workflows: Stand up one clean room integration for outcome reconciliation on a key account :cite[dse].
Phase 3: Productization
- Curated marketplace storefront: Searchable catalog, API docs, troubleshooting guides, and SLA commitments.
- PPS and Prebid hardening: Standardize PPS labels and Prebid ortb2 data pipelines across top publishers :cite[a41,ctt].
- Measurement program: Offer standard experiment templates and quarterly benchmarks by vertical.
- Revenue operations: Publish fee schedules and ensure finance systems handle segment fees or curated marketplace charges cleanly.
Frequently Asked Questions
Can buyers still bring their own data in an SSP-native marketplace
Yes, via clean rooms or deal-level allowlists. The marketplace should enable overlap analysis while keeping cohorts and raw identifiers private :cite[dse].
What happens if consent is not present
Default to contextual-only packages and suppress audience segments. Track the delta in reach and performance to guide consent optimization, and propagate GPP signals downstream :cite[bfd].
How do we avoid duplicative deals and audience fatigue
Use a catalog governance model. Every segment gets a unique definition, versioning, and deprecation policy. Provide overlap metrics to buyers to reduce redundancy.
Is this compatible with DSP SPO strategies
Yes. In fact, it helps. When sellers declare standardized segments on-object and enforce provenance checks, buyers can trust the signals and simplify their paths.
Conclusion
SSP-native audience marketplaces transform publisher knowledge into trusted, transactable signals. They do not depend on third-party identifiers. They lean on first-party cohorts, contextual strength, consent enforcement, and standardized taxonomies. The best implementations are boring in the right places. Standards heavy, privacy by design, and focused on operational excellence. Publishers who prepare their data and taxonomies, and SSPs that standardize signal orchestration, will win the next decade of addressability. The work is eminently practical. Start with a small catalog of high-intent segments, build forecasting discipline, and move buyers into clean measurement programs. Red Volcano exists to help the supply side move faster with evidence. We can show where you are ready, where you are brittle, and how to make your marketplace the most trustworthy source of addressable audiences in an ID-light world.
References
- IAB Tech Lab — Seller Defined Audiences (now Curated Audiences) — https://iabtechlab.com/sda/ — accessed 2025-09-02 :cite[ekx]
- IAB Tech Lab — Taxonomy and Data Transparency Standards — PDF — https://iabtechlab.com/wp-content/uploads/2022/02/IAB-Tech-Lab-Taxonomy-and-Data-Transparency-Standards-to-Support-Seller-defined-Audience-and-Context-Signaling.pdf — accessed 2025-09-02 :cite[duj]
- Prebid — First Party Data — https://docs.prebid.org/features/firstPartyData.html — accessed 2025-09-02 :cite[ctt]
- Google — About Publisher Provided Signals (PPS) — https://support.google.com/admanager/answer/12451124 — accessed 2025-09-02 :cite[a41]
- IAB Tech Lab — Global Privacy Platform (GPP) — https://iabtechlab.com/gpp/ — accessed 2025-09-02 :cite[bfd]
- IAB Tech Lab — Implementing app-ads.txt for Safer CTV — https://iabtechlab.com/implementing-app-ads-txt-for-safer-ctv-transactions/ — accessed 2025-09-02 :cite[as1]
- IAB Tech Lab — New CTV App Stores Added to App-ads.txt Aggregator — https://iabtechlab.com/new-ctv-app-stores-added-to-app-ads-txt-aggregator/ — accessed 2025-09-02 :cite[a9i]
- IAB Tech Lab — Data Clean Rooms Standards and Guidance — https://iabtechlab.com/datacleanrooms/ — accessed 2025-09-02 :cite[dse]
- IAB Tech Lab — Curated Audiences and Curation Framework — https://iabtechlab.com/curated-audiences-and-launching-the-curation-framework-working-group/ — accessed 2025-09-02 :cite[aqj]