AdCP — Commerce Media

Commerce media — advertising within retail and marketplace environments — lets brands reach shoppers at the point of purchase. AdCP’s retail_media channel handles the full spectrum: sponsored product listings, on-site display, off-site audience extension, premium placements, and in-store digital. What makes commerce media unique is closed-loop attribution. Retailers know what people buy. When ads run on retailer platforms, every impression can be tied to actual purchases — online and in-store. AdCP models this through outcome_measurement, conversion_tracking, and by_action_source in delivery reporting.

Concept Mapping

Retail Media Concept	AdCP Equivalent	Reference
Retailer / retail media network	Sales agent (MCP server)	`adagents.json`
Advertiser account with retailer	`account_id` + `list_accounts`	Accounts & Agents
Brand’s product catalog	`brand.product_catalog`	Brand identity
GTIN / SKU selection for promotion	Catalog selectors (`ids`, `gtins`, `tags`) on `Catalog`	Catalogs
Sponsored product listing	Product with catalog-rendered creative	Creative Formats
On-site display / video	Product with standard `format_ids`	Media Products
Retailer first-party audience	Brief-based; named segments via `data_provider_signals`	Targeting
ROAS target / max conversions	`optimization_goals` on package	Optimization & Reporting
Closed-loop measurement	`outcome_measurement` + `conversion_tracking` on product	Delivery Reporting
Attribution window (14d click, 1d view)	`attribution_window` in delivery response	Delivery Reporting
ROAS / attributed revenue	`roas`, `conversion_value` in delivery metrics	Delivery Reporting
In-store attribution	`by_action_source` with `in_store`	Delivery Reporting
Store locations / store locator	Store catalog (seller-provided or buyer-synced)	Catalogs — Stores
Real-time inventory / in-stock	Inventory catalog via `sync_catalogs`	Catalogs
Proximity / catchment targeting	Store catchment areas (isochrone, radius, GeoJSON)	Catalogs — Catchment areas

Each retailer is a separate sales agent. Their media offerings are modeled as products. The buyer’s brand identity carries the product catalog for SKU-level creative rendering. Account relationships between brands and retailers are managed via list_accounts and account on media buys — see Accounts & Agents.

The Product Spectrum

Major retailers like Walmart Connect, Kroger Precision Marketing, Target Roundel, and Carrefour Links offer diverse product types — not just sponsored listings. All share the retail_media channel, but differ in format, pricing, and creative requirements.

On-Site Display and Video

Display and video ads on retailer properties, targeted using retailer first-party shopper data. Buyers provide standard creatives. Higher minimums and CPMs reflect the value of retailer audience data and guaranteed placement.

{
  "product_id": "grocery_onsite_display",
  "name": "Category Shoppers - On-Site Display & Video",
  "description": "Display and video ads on retailer website and app, targeting shoppers with relevant purchase history.",
  "channels": ["retail_media"],
  "format_ids": [
    { "agent_url": "https://creative.adcontextprotocol.org", "id": "display_300x250" },
    { "agent_url": "https://creative.adcontextprotocol.org", "id": "display_728x90" },
    { "agent_url": "https://creative.adcontextprotocol.org", "id": "video_15s" }
  ],
  "delivery_type": "guaranteed",
  "pricing_options": [
    {
      "pricing_option_id": "onsite_cpm",
      "pricing_model": "cpm",
      "fixed_price": 14.00,
      "currency": "USD",
      "min_spend_per_package": 10000
    }
  ],
  "delivery_measurement": {
    "provider": "Retailer ad server with IAS viewability",
    "notes": "Impressions per IAB guidelines. MRC-accredited viewability."
  },
  "outcome_measurement": {
    "type": "incremental_sales_lift",
    "attribution": "deterministic_purchase",
    "window": { "interval": 30, "unit": "days" },
    "reporting": "weekly_dashboard"
  },
  "creative_policy": {
    "co_branding": "required",
    "landing_page": "retailer_site_only",
    "templates_available": true
  }
}

Note the creative policy: retailers commonly require co-branding and restrict landing pages to the retailer’s own site.

Off-Site Audience Extension

The retailer uses first-party purchase data to target audiences on third-party inventory — extending reach beyond the retailer’s own site. The product still belongs to the retail_media channel because the buying context is the retailer’s data asset.

{
  "product_id": "grocery_offsite_extension",
  "name": "Shopper Audiences - Off-Site Display & Video",
  "description": "Reach retailer shoppers across premium display and video inventory using first-party purchase data.",
  "channels": ["retail_media"],
  "publisher_properties": [
    { "publisher_domain": "grocery-retailer.com", "selection_type": "all" }
  ],
  "format_ids": [
    { "agent_url": "https://creative.adcontextprotocol.org", "id": "display_300x250" },
    { "agent_url": "https://creative.adcontextprotocol.org", "id": "video_15s" }
  ],
  "delivery_type": "guaranteed",
  "pricing_options": [
    {
      "pricing_option_id": "offsite_cpm",
      "pricing_model": "cpm",
      "fixed_price": 13.50,
      "currency": "USD",
      "min_spend_per_package": 10000
    }
  ],
  "delivery_measurement": {
    "provider": "Self-reported impressions from proprietary ad server",
    "notes": "Impressions counted per IAB guidelines. Viewability via IAS."
  },
  "outcome_measurement": {
    "type": "incremental_sales_lift",
    "attribution": "deterministic_purchase",
    "window": { "interval": 30, "unit": "days" },
    "reporting": "weekly_dashboard"
  }
}

Premium Placements

Homepage takeovers, category sponsorships, seasonal event placements. These high-visibility positions are sold at fixed rates with guaranteed delivery — often booked well in advance.

{
  "product_id": "grocery_homepage_takeover",
  "name": "Homepage Takeover - 24 Hours",
  "description": "Exclusive homepage banner and hero placement for 24 hours.",
  "channels": ["retail_media"],
  "format_ids": [
    { "agent_url": "https://creative.adcontextprotocol.org", "id": "display_970x250" },
    { "agent_url": "https://creative.adcontextprotocol.org", "id": "display_300x250" }
  ],
  "placements": [
    {
      "placement_id": "homepage_hero",
      "name": "Homepage Hero Banner",
      "format_ids": [{ "agent_url": "https://creative.adcontextprotocol.org", "id": "display_970x250" }]
    },
    {
      "placement_id": "homepage_sidebar",
      "name": "Homepage Sidebar",
      "format_ids": [{ "agent_url": "https://creative.adcontextprotocol.org", "id": "display_300x250" }]
    }
  ],
  "delivery_type": "guaranteed",
  "pricing_options": [
    {
      "pricing_option_id": "takeover_flat",
      "pricing_model": "flat_rate",
      "fixed_price": 50000.00,
      "currency": "USD"
    }
  ],
  "delivery_measurement": {
    "provider": "Retailer ad server",
    "notes": "Guaranteed impressions based on homepage traffic projections."
  },
  "creative_policy": {
    "co_branding": "required",
    "landing_page": "retailer_site_only",
    "templates_available": false
  }
}

Premium placements use the placements array so buyers can assign different creatives to different positions within the same product.

In-Store Digital

Digital screens in physical retail locations — checkout lanes, end-caps, and entrance displays. These bridge the digital-physical gap, with measurement tied to in-store purchases. When paired with a synced store catalog, in-store digital products can target specific locations and show inventory-aware creative.

{
  "product_id": "grocery_instore_screens",
  "name": "In-Store Digital Screens - Checkout & Aisle",
  "description": "Digital screens at checkout lanes and end-cap displays in 500+ locations.",
  "channels": ["retail_media"],
  "publisher_properties": [
    { "publisher_domain": "grocery-retailer.com", "selection_type": "all" }
  ],
  "format_ids": [
    { "agent_url": "https://creative.adcontextprotocol.org", "id": "display_1080x1920" },
    { "agent_url": "https://creative.adcontextprotocol.org", "id": "video_15s" }
  ],
  "delivery_type": "guaranteed",
  "pricing_options": [
    {
      "pricing_option_id": "instore_cpm",
      "pricing_model": "cpm",
      "fixed_price": 8.00,
      "currency": "USD",
      "min_spend_per_package": 5000
    }
  ],
  "delivery_measurement": {
    "provider": "Venue traffic sensors",
    "notes": "Impressions estimated from foot traffic data. Updated weekly."
  },
  "conversion_tracking": {
    "action_sources": ["in_store"],
    "platform_managed": true
  }
}

End-to-End Workflow

Closed-Loop Attribution

Commerce media’s defining advantage is deterministic purchase attribution. Retailers match ad exposure to transactions using loyalty card data, login state, and point-of-sale records.

How Products Declare It

Products signal closed-loop capability through two fields: outcome_measurement describes the attribution methodology:

{
  "outcome_measurement": {
    "type": "attributed_sales",
    "attribution": "deterministic_purchase",
    "window": { "interval": 14, "unit": "days" },
    "reporting": "daily_api"
  }
}

conversion_tracking declares action sources and whether the retailer manages measurement:

{
  "conversion_tracking": {
    "action_sources": ["website", "app", "in_store"],
    "supported_targets": ["cost_per", "per_ad_spend"],
    "platform_managed": true
  }
}

When platform_managed is true, the retailer provides always-on measurement. No buyer-side pixel or event source configuration needed.

Different retailers use different attribution windows (e.g., 14-day click vs. 7-day click). The attribution_window in delivery responses makes this transparent so buyers can normalize ROAS comparisons across retailers.

Key Delivery Metrics

Metric	Field	Description
Return on ad spend	`roas`	`conversion_value / spend`
Attributed revenue	`conversion_value`	Total purchase value attributed to ads
Conversions	`conversions`	Purchase events attributed to ads
Cost per acquisition	`cost_per_acquisition`	`spend / conversions`
New-to-brand rate	`new_to_brand_rate`	Fraction of conversions from first-time brand buyers
In-store sales	`by_action_source`	Breakdown by `website`, `app`, `in_store`
By event type	`by_event_type`	Breakdown by `purchase`, `add_to_cart`, etc.

Differences from Traditional Media Buying

Aspect	Traditional Media	Commerce Media
Attribution	Probabilistic, modeled	Deterministic, purchase-based
Targeting data	Third-party, contextual	First-party purchase/loyalty data
Primary KPIs	Impressions, clicks, CTR	ROAS, conversions, attributed revenue
Creative (sponsored)	Buyer-provided	Catalog-rendered by retailer
Measurement owner	Third-party (IAS, DV)	Retailer platform (`platform_managed`)
Conversion sources	Website only	Website + app + in-store
Landing page	Any destination	Often retailer site only
Pricing models	CPM, CPC, CPCV	CPC (sponsored), CPM (display), flat rate (premium)

Best Practices

For Brands

Set up accounts early — use list_accounts to confirm your billing relationship with each retailer before placing buys
Sync product and inventory feeds early — product and inventory catalogs should be synced to the account before creating buys. Inventory feeds update hourly; product feeds daily.
Reference retailer store catalogs in targeting — the retailer’s store locations and catchment areas are platform-side data. Use them for proximity targeting without needing to sync your own store catalog.
Use optimization_goals — set event goals with cost_per or per_ad_spend targets on packages to let the retailer optimize delivery against their purchase data
Use catalog selectors strategically — gtins for specific products, tags or category for broad promotions
Budget across the funnel — sponsored products for conversion, on-site display for awareness, off-site for reach extension
Compare attribution windows — use attribution_window in delivery reports to normalize ROAS across retailers with different lookback windows

For Retailers

Model product types separately — sponsored products, on-site display, off-site, and premium placements should be distinct products with appropriate pricing and formats
Declare catalog asset types on formats that need product or inventory data — buying agents check these before syncing catalogs
Declare conversion_tracking with platform_managed: true and list supported_targets so buyers know which target kinds are available on packages
Include attribution_window in delivery responses — buyers comparing across retailers need to know your lookback windows and model
Report by_action_source to show omnichannel impact — website, app, and in-store conversions
Return catalog_match on sponsored product listings so buyers can see which GTINs/SKUs are eligible
Provide store catalogs with catchment areas — expose your store locations with pre-computed or isochrone-based catchments so buyers can use proximity targeting. Resolve isochrone boundaries ahead of time so targeting doesn’t need runtime lookups
Set channels: ["retail_media"] on all commerce media products so buyers can filter by channel

Account state — How catalogs, event sources, and campaigns build on the account
Accounts & Agents — Account setup and billing relationships
Media Channel Taxonomy — retail_media channel definition
Media Products — Product model reference
Catalogs — Product, inventory, store, and promotion feeds
Brand identity — Product catalog and brand identity
Pricing Models — CPC, CPM, flat rate details
Optimization & Reporting — optimization_goals and conversion optimization
Delivery Reporting — Commerce attribution metrics
Targeting — Brief-based targeting approach

Getting Started

Building with AdCP

Protocol

FAQ

Trust & Security

Reference

Certification

Commerce Media

Concept Mapping

The Product Spectrum

Sponsored Product Listings

On-Site Display and Video

Off-Site Audience Extension

Premium Placements

In-Store Digital

End-to-End Workflow

Closed-Loop Attribution

How Products Declare It

Key Delivery Metrics

Differences from Traditional Media Buying

Best Practices

For Brands

For Retailers

​Concept Mapping

​The Product Spectrum

​Sponsored Product Listings

​On-Site Display and Video

​Off-Site Audience Extension

​Premium Placements

​In-Store Digital

​End-to-End Workflow

​Closed-Loop Attribution

​How Products Declare It

​Key Delivery Metrics

​Differences from Traditional Media Buying

​Best Practices

​For Brands

​For Retailers

​Related Documentation

Concept Mapping

The Product Spectrum

Sponsored Product Listings

On-Site Display and Video

Off-Site Audience Extension

Premium Placements

In-Store Digital

End-to-End Workflow

Closed-Loop Attribution

How Products Declare It

Key Delivery Metrics

Differences from Traditional Media Buying

Best Practices

For Brands

For Retailers

Related Documentation