Walmart puts ads inside its AI shopping agent
Sparky, Walmart's shopping agent, now shows sponsored prompts. In parallel, Marty opens as an advertising assistant for brands.
Mariano De Vitto · May 2026
Sparky, Walmart's shopping agent, now shows sponsored prompts. In parallel, Marty opens as an advertising assistant for brands.
Walmart confirmed this week that **Sparky**, its AI agent inside the app, is testing ads. The format is called a **sponsored prompt**: when a shopper asks Sparky something like "what soap should I buy for sensitive skin", the answer can include a paid recommendation before the organic one. The test started last fall in the US and is expanding now.
Marty, the other side of the counter
In parallel, Walmart Connect is launching **Marty**, an advertising assistant for brands. Marty builds sponsored search campaigns, suggests optimizations, and runs bids. It will be available to every brand buying search ads in the first half of 2026. Sparky's mirror image: Sparky is the shopper's agent, Marty is the advertiser's.
The number behind it
Walmart Connect grew **46% in 2025**, to nearly USD 6.4 billion. US ads business grew 33% for the year and 41% in Q4. Amazon Ads, the main rival, made USD 68 billion in 2025. The distance is still wide but Walmart's pace is double. And eMarketer analysts flag that Amazon and Walmart will take **89% of incremental retail media growth in 2026**.
What changes for a CPG brand
Two urgent questions this week. First: who decides which product shows up as a sponsored prompt when the shopper asks Sparky about a category? Walmart hasn't published the auction system yet. If you spend on Walmart Connect, ask your account team for the document on how paid vs organic answers are prioritized, what signals the model uses, and how cost per inclusion is calculated.
Second: how is it measured? The classic retail media metric (ROAS on a banner click) doesn't map cleanly to a conversational prompt. The shopper can see the recommendation, not buy in the moment, and come back three days later. Walmart will have to show multi-touch attribution that closes against the basket. Ask for it.
The editorial asterisk: when the search agent recommends a paid product without a crisp ad disclosure, the regulatory risk is high. Walmart says clear disclosure will be visible, but FTC rules for native advertising inside conversational interfaces are still in motion. Legal will want the fine print.
The signal: Retail media moved into the AI shopping layer. If you sell at Walmart, demand the Sparky auction document this week and build the measurement plan for sponsored prompts.
The Signal Brief · Mariano De Vitto — Head of Marketing, Barcelona