Assistants choose between platforms — and between your sellers.

---
title: Assistants choose between platforms — and between your sellers.
canonical: https://chosenbyagent.com/for/marketplaces
updated: 2026-10-22
audiences:
  - marketplaces
offers:
  - A5
  - A1
  - A2
  - A3
  - A4
  - A6
  - A7
description: Where AI assistants send buyers in your markets, how they show your listings and sellers, and whether your ChatGPT app or MCP holds up — for marketplaces.
---

# Assistants choose between platforms — and between your sellers.

For Marketplaces

You own the shelf. A buyer who asks an assistant for a used car, a flat or a road bike first gets sent to a platform — yours, a horizontal competitor or a specialist — and then to a handful of listings on it. Both choices are made by models you do not control, and both shift with every release.

We measure where assistants route buyers in your markets and languages, whether the listings they show are still live at the right price with a working deep link, which of your sellers they surface, and how your own AI channel and the agents in your chats behave.

## Where agents choose for you

- **Level 1 · Channel** — Which platform or store to open. Marketplaces compete with each other and with brand stores.
- **Level 2 · Listing** — Which listing and seller to show. Sellers compete inside a marketplace; the platform owns the shelf.
- **Level 4 · Action** — Getting through the path and the deal. Stores and platforms decide whether an agent gets through — and how it behaves.

## Your questions

### Which platform or store to open

Level 1 · Channel. Marketplaces compete with each other and with brand stores.

- [Q01 · Where do AI assistants send my buyers?](/questions/where-do-assistants-send-buyers.md) — Marketplaces, Brands · A2 Routing & listing audit · from €2,500 (one-off)
- [Q08 · What changed after the last model update?](/questions/what-changed-after-the-update.md) — Marketplaces, Sellers, Brands · A6 Monitoring · from €800 (per month)

### Which listing and seller to show

Level 2 · Listing. Sellers compete inside a marketplace; the platform owns the shelf.

- [Q02 · Do assistants show my listings correctly?](/questions/are-my-listings-shown-right.md) — Marketplaces, Sellers · A2 Routing & listing audit · from €2,500 (one-off)
- [Q03 · Does my ChatGPT app or MCP work as intended?](/questions/does-my-ai-app-work.md) — Marketplaces · A3 AI channel check · from €3,000 (one-off)
- [Q11 · Which of my sellers do AI assistants surface — and why?](/questions/which-sellers-do-assistants-surface.md) — Marketplaces · A7 Seller insights for platforms · from €4,000 (one-off)

### Getting through the path and the deal

Level 4 · Action. Stores and platforms decide whether an agent gets through — and how it behaves.

- [Q04 · Do buyer and seller agents behave safely on my platform?](/questions/are-agents-safe-in-my-chats.md) — Marketplaces · A4 Agent red team · from €5,000 (one-off)

## Services and prices

- **A5 Marketplace pilot** — from €7,500 (one-off) · 4 weeks · €10,500 if bought separately. Routing & listing audit, AI channel check and agent red team, calibrated against your assistant referral traffic.
  - For: Marketplaces
  - Everything in A2, A3 and A4
  - Calibration against your assistant referral traffic
- **A1 Public benchmark** — Free, in preparation (not requestable yet). Where AI assistants route demand across European classifieds.
  - For: Marketplaces
  - Buyer intents in 5 markets and 4–5 languages
  - ChatGPT, Gemini and Claude with web search
  - About 12,000 queries and 200 manual calibration runs
- **A2 Routing & listing audit** — from €2,500 (one-off). Where assistants send your buyers, how they show your listings, and what to fix first.
  - For: Marketplaces
  - Routing share against named competitors, with the reasons assistants give
  - Listing quality: live or sold, price match, deep link, attribution
  - Agent access: WAF blocks, JS-only content, missing schema
  - Manual calibration in the consumer apps
  - Prioritised fixes, each stamped with model and date
  - Answers: [Q01](/questions/where-do-assistants-send-buyers.md), [Q02](/questions/are-my-listings-shown-right.md)
- **A3 AI channel check** — from €3,000 (one-off). Your ChatGPT app, MCP or agent gateway — freshness, attribution, and contact staying on your platform.
  - For: Marketplaces
  - Correctness and freshness of what your app returns
  - Attribution and deep links back to your listings
  - Contact and payment kept on the platform
  - Answers: [Q03](/questions/does-my-ai-app-work.md)
- **A4 Agent red team** — from €5,000 (one-off). How buyer and seller agents behave in your chats, tested in your sandbox.
  - For: Marketplaces
  - Address and phone leaks
  - Agreeing to prepayment or below-price deals
  - Taking the deal off the platform
  - Scams and prompt injection in listings
  - Answers: [Q04](/questions/are-agents-safe-in-my-chats.md)
- **A6 Monitoring** — from €800 (per month). A monthly baseline and re-runs after model releases, with a versioned history and alerts.
  - For: Marketplaces
  - Monthly baseline run
  - Event-driven re-runs after model releases
  - Versioned history and alerts on shifts
  - Answers: [Q08](/questions/what-changed-after-the-update.md)
- **A7 Seller insights for platforms** — from €4,000 (one-off). Which of your sellers and listings assistants surface, and why — with white-label reports your professional sellers can buy.
  - For: Marketplaces
  - Which sellers and listings assistants show and pick, by category and market
  - What moves the choice: price, rating, delivery, returns, listing quality
  - How your own seller quality signals line up with the agent's choice
  - White-label seller reports for your pro-seller programme
  - Answers: [Q11](/questions/which-sellers-do-assistants-surface.md)

## Tell us what you want tested.

Audits and pilots get a scope, a fixed price and a start date. The free snapshot comes straight to your inbox.

Agents: POST /api/engagements (application/json) with {"offer_id": "A5", "on_behalf_of": {"email": "…"}, "agent": {"name": "…"}}. offer_id for this page: "A5" Marketplace pilot; "A2" Routing & listing audit; "A3" AI channel check; "A4" Agent red team; "A6" Monitoring; "A7" Seller insights for platforms. The person confirms by email before we see the request. Details: /agents.md