In 2009, developers who understood one thing about the App Store did very well: rank was driven by downloads, and downloads were driven by rank. Whoever got that loop going first tended to own their category. The tactics changed every year. The structure of the game didn't.
That game has restarted.
I had a closer view of the first round than most: I led product analytics for the Google Play Developer Console, building the tools publishers used to improve their apps and get discovered on the store. What follows is that playbook, replayed for a new shelf.
Claude and ChatGPT both run curated marketplaces where users discover and connect MCP servers: Anthropic's Connectors Directory and the ChatGPT app directory. A community tracker counts over 700 integrations in the Claude directory, used by millions of people. These aren't developer indexes. They're storefronts inside the products where your users already work. When someone connects your server, they're giving an assistant standing permission to use your product on their behalf in any future conversation where it fits.
The important detail is in Anthropic's directory documentation: ranking is usage-based, "similar to other app stores". Your position on the shelf depends on how many people actively use your connector. Not the quality of your listing, not when you launched. Usage.
The flywheel, and why timing matters
Usage-based ranking creates a loop. Active users improve your rank, rank gets you discovered, discovery brings new users. Loops like this are hard to enter late and generous to whoever enters early. The connectors above you today are compounding their lead.
One detail suggests how early it still is: there are no ratings or reviews. No stars, no written feedback, no social proof. Rank carries the whole discovery signal. That's roughly the 2009 condition, and if the App Store is any guide, reviews will arrive eventually. When they do, early movers will have incumbency in the rankings plus a head start on accumulated usage. So there's a window right now where usage growth alone moves you up the shelf, and it won't stay open indefinitely.
Playing it: get your existing users onto the channel
A quirk of usage-ranked marketplaces is that they reward the users you bring, then pay you back with users you didn't. Early App Store winners drove their own installs first, through press, email lists and cross-promotion. Organic discovery followed the rank, not the other way round.
The MCP version, if you already run a SaaS product, is simple and mostly unexploited:
Tell your users the connector exists. An email to your customer base saying "you can now use us inside Claude and ChatGPT" is probably the highest-leverage single action available, and most companies with a live connector haven't sent it. Every customer who connects becomes an active user pushing your rank.
Put the connection where the work is. A prompt inside your product, a docs page, a line in onboarding. These are existing customers, so you're not acquiring anyone. You're routing people you already have onto a channel where their usage now also counts towards your rank.
Concentrate the launch. Rank responds to usage velocity, so an announcement, an email and community posts in the same fortnight will do more than the same effort spread over a quarter. The loop needs an initial push.
Ads are coming, to one of the shelves
If your reaction to all this is "surely placement just goes to whoever pays", you're partly right. The two platforms have split on this question. OpenAI has announced plans to bring ads to parts of ChatGPT, and its commercial machinery is already visible in launch-partner featuring and checkout fees. Anthropic has pledged the opposite: Claude products will stay ad-free, with third-party integrations initiated by the user rather than an advertiser.
The App Store has seen this before too. Search ads arrived in 2016 and organic optimisation mattered more afterwards, not less, because paid buys the trial and quality keeps the rank. Expect the same split here: on any shelf where placement can be bought, big brands will buy it, and everyone else competes on the levers in this post. And the second ranking, the one covered next, isn't for sale on either platform, because a model that keeps choosing tools that fail would be degrading its own product.
The second ranking nobody can see
Marketplace rank gets you connected. After that there's a second, invisible ranking: the model itself decides, in each conversation, whether to call your tools. Both platforms also suggest relevant connectors mid-task: Claude's directory entries are eligible for Suggested Connectors, and OpenAI says apps meeting higher standards may be featured more prominently, in the directory and in conversations. Which means your tool names, descriptions and schemas are being read and judged by a language model at runtime.
There's no App Store precedent for this. The OS never decided, per use, whether your app deserved to run. Clear, narrow tool names get selected. Vague ones get routed around. A description like "makes a request to the API" loses the selection every time to a competing tool that says what it does.
Usage-based ranking makes agent experience a growth metric
Put the two layers together. An active user isn't someone who connected once; it's someone whose agent kept coming back. And agents are unsentimental users. When a tool call errors, returns something unusable, or silently drops a parameter, the agent adapts. It retries, routes around you, or finishes the task without you. Your server logs show status 200 throughout. Meanwhile your active-user count stops growing, and your rank follows it.
The agent won't tell you it failed. It'll just stop coming back. In a usage-ranked marketplace, that's a distribution problem, not just a product one.
Anthropic seems to see it the same way. Connector publishers now get a dashboard showing active users, tool calls, error rates and directory rank over time, side by side. Rank is presented as a metric downstream of usage health, because it is. The work, then, is the same loop good product teams have always run: find where the experience breaks, fix the biggest break, check whether usage moved, repeat. The user under the microscope just happens to be an agent.
The short version
The App Store era gave us ASO. This one needs a name too, so I'll propose one: AXO, agent experience optimisation. Getting listed, getting chosen by the model, and getting chosen again, treated as one discipline, because the marketplaces have wired all three together.
So: get listed on both storefronts. Push your existing users onto the channel this quarter, while rank is the whole game and reviews don't exist. Write your tool metadata for the model that reads it. And treat agent experience as a ranking factor, because now it is one.
Sources
- Connectors directory — Claude documentation (usage-based ranking, Suggested Connectors)
- Observability for developers building connectors — Anthropic (publisher dashboard: active users, tool calls, errors, directory rank)
- awesome-claude-connectors — community tracker (integration counts, updated weekly)
- Developers can now submit apps to ChatGPT — OpenAI (app directory and review process)
- Introducing apps in ChatGPT — OpenAI (in-conversation app suggestions and featuring)
- App submission guidelines — OpenAI Apps SDK (quality and distribution criteria)
- Claude is a space to think — Anthropic (ad-free policy, user-initiated integrations)
- Anthropic says Claude will remain ad-free as ChatGPT tests ads — Search Engine Land (the platforms' diverging ad positions)
If you build a surface that agents use, and you want to know how they actually use it, Vesta is in early access.