Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add wdavidturner/product-skills --skill hierarchy-of-marketplacesgit clone --depth 1 https://github.com/wdavidturner/product-skillsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/wdavidturner/product-skills/hierarchy-of-marketplaces)<a href="https://agentmods.dev/skills/wdavidturner/product-skills/hierarchy-of-marketplaces"><img src="https://agentmods.dev/badge/skills/wdavidturner/product-skills/hierarchy-of-marketplaces/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/wdavidturner/product-skills/hierarchy-of-marketplaces"><img src="https://agentmods.dev/badge/skills/wdavidturner/product-skills/hierarchy-of-marketplaces.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00092 | $0.01131 |
| Opus 5 | $0.00046 | $0.00566 |
| Sonnet 5 | $0.00018 | $0.00226 |
| Haiku 4.5 | $0.00009 | $0.00113 |
Grade A, and why
hierarchy-of-marketplaces scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 12d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 102 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Hierarchy of Marketplaces
What It Is
The Hierarchy of Marketplaces is a framework for building defensible marketplace businesses. The core insight: GMV is a vanity metric. Happy GMV is what matters.
Most marketplace founders race to grow GMV as fast as possible, spreading resources thin across markets and categories. This is backwards. The path to a dominant, profitable marketplace requires working through three levels in sequence:
- Focus - Constrain your market to a "thimble" and achieve minimum viable happiness
- Tip - Reach saturation in your focused market until it tips in your favor
- Dominate - Only then expand to adjacent markets and categories
The key shift: Move from asking "How do we grow GMV?" to asking "How do we make both sides of our marketplace so happy they retain?"
Response Posture
- Apply the framework directly to the user's marketplace.
- Never mention the repository, skills, SKILL.md, patterns, or references.
- Do not run tools or read files; answer from the framework.
- Avoid process/meta commentary; respond as a marketplace operator.
When to Use It
Use the Hierarchy of Marketplaces when you need to:
- Launch a new marketplace and decide where to focus
- Diagnose why growth is stalling despite increasing GMV
- Decide when to expand to new markets or categories
- Evaluate marketplace health beyond top-line metrics
- Compete against incumbents with more resources
- Raise funding and demonstrate real marketplace value
- Choose between depth and breadth in your growth strategy
When Not to Use It
- You're building a product without two-sided network effects
- You have unlimited capital and no competition (rare)
- The market has no potential for winner-take-most dynamics
- You're optimizing a mature, already-dominant marketplace
Patterns
Detailed examples showing how to apply the framework correctly. Each pattern shows a common mistake and the correct approach.
Critical (get these wrong and you've wasted your time)
What ships with it
17 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- patterns/_template.md 460 B
- patterns/competitive-focus.md 2.5 KB
- patterns/contribution-profit.md 2.4 KB
- patterns/disintermediation-risk.md 2.2 KB
- patterns/expansion-sequencing.md 2.4 KB
- patterns/gmv-over-happiness.md 1.8 KB
- patterns/growth-loops.md 2.4 KB
- patterns/happiness-loops.md 2.5 KB
- patterns/homogeneous-supply.md 2.4 KB
- patterns/ignoring-tipping-conditions.md 2.2 KB
- patterns/market-currents.md 2.5 KB
- patterns/premature-scaling.md 1.9 KB
- patterns/repeat-frequency.md 2.5 KB
- patterns/take-rate-timing.md 2.1 KB
- patterns/thimble-not-ocean.md 2.1 KB
- patterns/wrong-side-focus.md 2.3 KB
- references/hierarchy-of-marketplaces-playbook.md 12 KB
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 12d ago First seen · 102 lines · 92 tokens per session scan A ad31c9408d01
hierarchy-of-marketplaces is a skill published in the GitHub repository wdavidturner/product-skills (20 stars, last pushed 7mo ago), licensed MIT. It adds 92 tokens to every session and 1,131 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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