Google Ads has published new documentation for Commerce Audience Sharing, a framework that lets retailers and marketplaces share selected first-party audience segments with advertising partners such as brands and sellers. The feature formalizes a retail-media relationship that is becoming increasingly important as commerce platforms look for ways to activate their customer data while brands seek stronger first-party signals for campaigns.
Google describes the system in its new Commerce Audience Sharing help documentation. Barry Schwartz highlighted the new help page at Search Engine Roundtable on September 18, 2026. The core model is straightforward: a commerce partner — typically a retailer or marketplace — chooses audience segments to share, and an eligible advertising partner can use those segments in supported commerce media campaigns.
The retailer shares the audience, but keeps control of the destination
One of the most important restrictions is where the resulting advertising traffic can go. Google says any campaign using a commerce partner's shared audience can only direct users back to the commerce partner's approved website. A brand receiving a retailer's shopper segment therefore cannot simply use that audience to divert the same consumers to its own direct-to-consumer store or another marketplace.
That design gives retailers a strong incentive to participate. Their first-party audience data can help partner brands run more relevant campaigns, but the commercial activity remains tied to the retailer's platform. In effect, the retailer contributes the audience intelligence while Google Ads supplies the campaign infrastructure and the brand contributes advertising spend and product demand.
Google says commerce partners retain controls over which audiences are shared and which advertising partners receive them. Shared audiences appear with a “Shared” badge in Audience Manager, and the commerce partner can stop sharing a segment later through the same interface.
Brands can combine retailer audiences with their own first-party data
For brands and sellers, the appeal is access to customer signals they normally would not own. A retailer may know which shoppers visited a category, purchased a particular type of product or belong to another valuable first-party segment. Once the retailer shares an eligible segment, the advertising partner can apply it to supported campaigns and combine it with its own first-party audience data.
Google says Commerce Audience Sharing supports available and eligible audience types within Google Ads, although the normal requirements for each audience type still apply. Customer Match, for example, continues to require both participating accounts to meet Google's Customer Match eligibility criteria. Commerce Audience Sharing does not override the underlying audience policies simply because two partners have linked their accounts.
The setup requires Ads, Merchant Center and data-sharing links
This is not an open audience marketplace where any advertiser can request a retailer's customer data. Google requires an explicit account relationship. To use Commerce Audience Sharing, the advertising partner's Google Ads account must be linked to the commerce partner's Google Merchant Center account and to the commerce partner's advertising data-sharing account.
Google directs advertisers to Data Manager to confirm those relationships under Connected products. The commerce partner must also already have relevant audience segments in its data-sharing account. Only actively linked advertising partners appear as available recipients when the retailer chooses the “Share with partners” action in Audience Manager.
The commerce partner can specify the approved domain associated with the relationship, reinforcing the rule that shared-audience campaigns must return traffic to the retailer or marketplace. Google also notes that accepting the data-sharing link does not grant the commerce partner direct access to the advertising partner's Google Ads account.
The two sides do not receive exactly the same data
Google's documentation also explains how reporting is divided. The commerce partner can access campaign-related performance and spend metrics, including information associated with impressions, clicks and conversions. The advertising partner can see information about the segments that were shared, such as segment name, customer type, list size and membership status, together with conversion-related performance data from the commerce partner's website.
This makes the arrangement more than a simple targeting handoff. It creates a measurable collaboration in which the retailer can evaluate the advertising activity driven by its audience assets while the brand can understand how the shared segments contribute to campaign outcomes. Exactly how organizations operationalize those metrics will depend on their commercial agreements, but Google Ads now provides a documented technical structure for the exchange.
Commerce Audience Sharing is built for retail media
The feature should be understood primarily as part of Google's commerce-media strategy rather than as a general-purpose audience-sharing tool. Google says shared commerce audiences can only be used with eligible commerce media network campaigns. The documentation identifies two principal scenarios: campaigns that commerce partners run on behalf of advertising partners, and self-service campaigns that advertising partners operate themselves.
That distinction matters because retail media has traditionally been fragmented across retailer-specific ad platforms and managed-service arrangements. A brand selling through several large retailers can face different interfaces, data definitions and activation workflows for each partner. Google's approach brings at least part of that relationship into Google Ads, a platform many brand advertising teams already use.
For retailers and marketplaces, the value proposition is equally clear. First-party shopper data becomes an advertising asset that can be selectively activated with trusted suppliers without handing those partners unrestricted control over the customer relationship. Because traffic must return to the approved commerce-partner domain, the retailer can use audience sharing to help brands generate incremental sales on the retailer's own property.
First-party data is becoming a collaboration layer
The broader significance is the way Google is treating first-party data. Instead of assuming that each advertiser operates only with its own customer signals, Commerce Audience Sharing recognizes that modern ecommerce often involves several parties with different pieces of the customer relationship. A retailer knows how shoppers behave on its marketplace; a brand understands its product customers and marketing history; the campaign can potentially become more useful when those signals are combined under controlled conditions.
That does not eliminate privacy and governance responsibilities. Businesses still need to meet Google's audience requirements and their own legal obligations for collecting, processing and sharing customer data. The new documentation describes platform controls and eligibility rules, but those controls do not replace the need for appropriate consent, contractual arrangements and internal data governance.
Why search marketers should still pay attention
Commerce Audience Sharing is primarily a paid-media development, not an organic Search ranking update. It does not change crawling, indexing or conventional SEO rankings. But for ecommerce search marketers, the separation between Shopping, retail media, Merchant Center data and audience activation continues to narrow, making developments in Google Ads increasingly relevant to the wider commerce-search ecosystem.
The feature is particularly notable alongside Google's broader investment in commerce experiences and first-party data infrastructure. Merchant Center supplies the retailer relationship, Data Manager supplies the account connections, Audience Manager controls the segments and Google Ads supplies the activation layer. Rather than functioning as isolated products, those components increasingly form one commerce advertising stack.
For retailers and marketplaces with strong customer datasets, Commerce Audience Sharing turns audience knowledge into a controlled partner asset inside Google Ads. For brands and sellers, it creates a route to target consumers using signals generated closer to the actual point of purchase. The key constraint — and arguably the feature that makes the arrangement commercially viable for retailers — is that the shared audience can help a brand advertise, but it cannot be used to take the retailer's shopper somewhere else.