The cart is the product now

Forty-two per cent. That's the conversion lift Adobe attributes to shoppers who arrive at a merchant's site via AI referral, according to Digital Commerce 360's coverage of Klarna's new ChatGPT integration. Not forty-two per cent more browsing, more clicking, more "adding to wishlist." More buying. If you want to understand why Google, Klarna, and OpenAI suddenly care about shopping carts, that number is the entire explanation compressed into a single data point.

The protocol war nobody asked for

Google just launched Universal Cart, a persistent shopping layer that works across Search, Gemini, YouTube, and Gmail, surfacing price drops, tracking history, flagging restocks. Klarna simultaneously plugged its catalogue into ChatGPT, making OpenAI's chatbot a major AI-powered shopfront. And Fast Company found Google, OpenAI, and others racing to build the plumbing through which agentic purchases flow.

The conventional read: AI is getting better at recommending products. The sharper story: the fight is shifting towards who holds the basket.

Think about what a cart really is. It's an intent register, not a feature. The moment a user adds an item, you know what they want, what they'll compare it against, and what price threshold triggers a purchase. That's not commerce infrastructure. That's an attention monopoly with a payment form attached.

The parallel I keep coming back to is interchange. Visa and Mastercard never manufactured a single product. They never ran a shop. They inserted themselves into the moment of transaction and took a percentage of everything that flowed through. The economics were so good precisely because they were invisible; people rarely switch payment rails mid-purchase. The emerging agentic commerce protocols are bids to become that invisible layer, except now the rail also decides what you see before you buy.

This is why Google's announcement buries the interesting bit in the infrastructure section: Universal Cart is built on a commerce protocol that "enables AI agents to communicate with payments infrastructure." The cart is the protocol's consumer-facing justification. The protocol is what actually matters; it's what locks merchants in and makes switching costs real.

For builders, the implication is uncomfortable. If you're a merchant connecting to these commerce layers, you're trading margin for traffic from buyers who convert at dramatically higher rates. That looks like a good deal until you realise the platform now owns the customer relationship, the comparison context, and the re-engagement trigger. You become a fulfilment endpoint.

Fast Company quotes a Forrester analyst saying nobody has figured this out yet. I'd frame it differently: the incentives are clear. The fight just has not produced a winner yet. The tipping point is months away, not years.

The question for anyone building product right now: when the AI layer owns the cart, what does your checkout page even mean? The answer might be: less than your wholesale agreement with whoever controls the basket.

---