Agentic Commerce: Strategic Allies or an Existential Threat to Marketplaces?

Amazon has updated its legal policies to control exactly how AI agents can interact with its platform, banning behaviors that mimic humans or bypass CAPTCHAs, and reserving the right to cut off access “at its sole discretion.” It’s also blocked major AI crawlers from Meta, Google, and Huawei to prevent them from scraping product pages and prices.

But Amazon isn’t just playing defense. It’s building its own agent, Buy with Me, designed to purchase products even from outside Amazon, while keeping users inside its ecosystem. The message is clear: we’ll do agentic commerce, but the agent will be ours.

eBay took a different approach, banning unauthorized AI agents from placing orders while piloting its own agent and staying open to partnerships with third parties, on eBay’s terms. Think authentication requirements, usage limits, and strict data governance rather than open scraping.

The biggest fear is simple: if an AI agent can compare offers across platforms and complete purchases without users ever visiting Amazon or eBay, those browsing sessions disappear. And the entire retail media model – where brands pay for sponsored placements and search results – depends on those sessions.

AI agents threaten to short-circuit this by selecting products based on user preferences and value rather than who paid the most for visibility.

There’s also a deeper issue: customer ownership. In an agent-driven world, shoppers entrust their preferences, payment info, and purchase history to the AI assistant, not the marketplace. The agent becomes the interface; the marketplace becomes invisible infrastructure. For companies that have spent years building loyalty programs and ecosystems, that’s a hard pill to swallow.

Add compliance risks (agents making mistakes with prices or policies), reputational concerns (being blamed for AI hallucinations), and technical burdens (poorly designed agents hammering servers), and you have a perfect storm of defensive moves.

Here’s where it gets interesting. Instead of blocking agents entirely, the industry is moving toward agentic commerce protocols, standardized ways for agents to access catalogs, build carts, and complete purchases. OpenAI announced one with Stripe. Shopify is building its own. And Google just launched the Universal Commerce Protocol.

Marketplaces aren’t banning agents in this model. They’re choosing which ones to work with, negotiating what data gets exposed, and maintaining some control over product presentation. Meanwhile, they’re building their own agents to keep the orchestration value in-house.

The shift is from “rogue agents scraping everything” to “certified agents with API access,” where the power still sits with the platforms.

For brands selling on marketplaces, the question isn’t who wins this battle. It’s how to adapt when your buyer is increasingly an AI rather than a human.

• Data quality becomes critical: AI agents need structured product information: clear titles, complete attributes, consistent pricing, detailed logistics. Listings with messy data won’t get recommended, even if they perform well in ads or search. This makes centralized feed management and data discipline, the core of what platforms like Lengow do.
• Think cross-platform: When an agent compares Amazon, eBay, and your D2C site simultaneously, you can’t optimize in silos anymore. Price consistency across channels, availability, and delivery promises all matter. Being selected as the “best option” in a multi-platform comparison is the new game.
• Operational excellence matters more: Agents arbitrate on explicit criteria – budget, timing, preferences – not just paid placement. This could level the playing field for sellers who nail the fundamentals but haven’t mastered retail media bidding wars.

Marketplaces aren’t blocking AI agents. They’re trying to control them, steering agentic commerce into walled gardens where they still own the customer relationship and ad inventory.

For brands, this new reality means structured data isn’t just best practice anymore, it’s basically survival. Cross-platform consistency matters more than ever. And the relationship between marketplaces and merchants is being renegotiated in real time.