Marketing Skills by Corey Haines: package review

Marketing Skills is Corey Haines' package of marketing instructions, published in the coreyhaines31/marketingskills repository. It covers work such as copywriting, SEO, conversion optimisation and analytics. This review examines that specific project: what it includes, how to install it, the context it needs and its limitations.

To compare tools and packages from different authors, explore the marketing skills for AI agents collection. This page focuses on Marketing Skills and what to check before adding it to your workflow.

TL;DR: The No-Nonsense Summary

• 50 marketing skills: Markdown instructions that give CRO, SEO, ads, copywriting, and analytics context to agents like Claude Code, Cursor, Codex, or Windsurf.
• Free and MIT: no API key, no subscription, one command to install.
• Smart root document: product-marketing.md defines your product and audience; all other skills read that context before acting.
• English only: instructions, templates, and documentation. Getting output in another language requires asking explicitly.

Verdict: if you already work with code agents and do marketing, there's no reason not to try it. It's free, installs in a minute, and the worst case is you delete a folder.

The Problem It Solves

Code agents are powerhouses for programming, but marketing is not just code. It's strategy, user psychology, understanding the doubts that stop someone from buying. And there, these agents are flying blind.

Tell it to "optimize this landing page" and it changes a button color. Ask for an email sequence and it produces five generic emails that could belong to any SaaS on the planet. The agent needs marketing context to make those decisions.

Marketing Skills attacks exactly that. These are Markdown files (specialized instructions) that give the agent the knowledge it's missing: CRO frameworks, SEO best practices, Google Ads and Meta campaign structure, A/B testing logic, cold email copy, and 50 specialties in total.

Plain text files that live inside your project. No interface, no subscription. The agent reads them when it detects you're working on a marketing task. The author is Corey Haines, who also runs Conversion Factory (a CRO agency) and Swipe Files (a marketing newsletter).

Getting Started

Installation is one command. Literally one.

npx skills add coreyhaines31/marketingskills

The CLI detects which agent you have installed and asks where to place the files. For Claude Code they go to .claude/skills/; for others, to .agents/skills/. If you'd rather pick specific skills instead of all 50:

npx skills add coreyhaines31/marketingskills --skill cro copywriting ads

There are other routes: clone the repo, Git submodule, Claude Code plugin (first /plugin marketplace add coreyhaines31/marketingskills, then /plugin install marketing-skills). But npx is the fast lane and what the documentation recommends.

The only real requirement is having Node.js and a compatible agent: Claude Code, Cursor, Codex, Windsurf, or anything that supports the Agent Skills spec. The repository is MIT-licensed, and installing these skills doesn't require a separate account or API key.

One detail the README buries: if you run the command from inside an agent session (telling Claude Code to "install marketing skills"), the CLI may install to the wrong path. For Claude Code, pass the explicit flag: -a claude-code.

Using It in Real Marketing

Marketing Skills makes sense if you already live inside a code agent day-to-day. This review is based on the project's public documentation; we haven't tested the skills firsthand.

The product-marketing skill acts as the root document: it records the product, audience, positioning, and value proposition. The other skills consult that context before acting.

For an agency managing multiple accounts, that's powerful. Each project has its own product-marketing.md and the skills adapt without rewriting anything. Ask the agent to "review this page for conversion" and, with the CRO skill loaded, it has the frameworks to flag unnecessary form fields, a buried CTA, or missing social proof.

The ads skills cover Google Ads, Meta, LinkedIn, and Twitter/X campaigns. The analytics skill sets up GA4 tracking with proper judgment. The ai-seo skill handles AI search optimization (AEO). And they cross-reference each other: copywriting talks to cro, revops talks to sales-enablement, seo-audit talks to schema. Those connections are documented in the repository. If you're interested in how AI agents are changing marketing workflows, this is giving them an operations manual instead of letting them improvise.

That root document deserves some time. Writing "we sell software" in product-marketing.md leaves out the detail the agent needs to adapt its recommendations to the business. I'd start with the objections that come up in sales conversations and explain why a customer would choose you.

What They Do Not Tell You

The instructions and documentation are in English. If you work in another language, specify the output language and the market the work is aimed at.

The project has verified partners: Converly (server-side conversion tracking) and Ploy (AI-powered website platform). The README claims they don't influence what the core skills recommend, and there's a public ruleset document in the repo. Worth keeping in mind: when a skill suggests tools, file that away.

And there's a risk no README will ever admit: the skills are static files. Google Ads changes something every quarter, Meta rewrites its ad policies regularly, and SEO best practices shift with every algorithm update. A Markdown file written in June can be outdated by September. The repo has recent activity (last updated September 5, 2026, with an active community behind it), which is a good sign. But 50 skills are a LOT of skills to keep current. This is, in my view, the most serious long-term weakness: keeping the instructions current takes sustained work. The website lists the two verified skill partners separately from its sponsors and supporters; both groups support the project.

Verdict

Marketing Skills fills the biggest gap in code agents: they program beautifully, but marketing is their blind spot. And that alone is enough.

I'd start with a page that needs a CRO review. Keep the task small. Then check the skill's recommendations against the problem you're trying to solve before using it across more work.

Of all the marketing resources for AI agents out there right now, Marketing Skills is among the most complete.

Install the Marketing Skills library in this project. Run: npx skills add coreyhaines31/marketingskills -a claude-code. Then read the CRO skill and use it to audit the project's main page for conversion.