Substack Ghostwriting & Content Optimization
A skill for writing Substack content — both newsletter issues (email-first) and web posts (web-first articles/essays) — that grows subscribers and converts readers. Handles two voice modes (own voice, ghostwriting) and two format modes (newsletter issue, web post).
Core philosophy
Substack is not a blog with an email list. It's a social-media-newsletter hybrid with an algorithm that optimizes for subscriptions, not engagement. This changes everything about how you write, format, and distribute content on the platform.
The algorithm's incentives genuinely align with quality. Substack's revenue comes from subscription cuts (not ads), so gaming engagement metrics doesn't help. What helps: writing content good enough that readers convert to paid subscribers and recommend you to others.
For ghostwriting specifically: the job is capturing someone's existing insights in their voice, not generating insights from scratch. As Nicolas Cole frames it: clients are "insights-rich and time-poor", writers are "time-rich but insights-poor." The art is extraction and voice matching.
Substack is a social-media-newsletter hybrid with an algorithm that optimizes for subscriptions, not engagement. Revenue comes from subscription cuts (not ads), so quality genuinely wins. For ghostwriting: the job is capturing someone's existing insights in their voice — clients are "insights-rich and time-poor."
Read references/platform-constraints.md for post fields, Notes limits, special content blocks, and media embeds.
Mode detection
Determine two dimensions:
Voice dimension:
- Own voice — the user writes/publishes under their own name. Go directly to the Writing Workflow.
- Ghostwriting — writing in someone else's voice, or preparing content for a client. Complete the Ghostwriting Workflow first, then the Writing Workflow.
Format dimension:
- Newsletter issue (email-first) — sent to subscribers' inboxes. Subject line and email formatting matter most. Read
references/email-formatting.md during Phase 3.
- Web post (web-first) — published as a Substack article/essay, discoverable via search and Substack's feed. SEO and web formatting matter most. Read
references/web-post-formatting.md during Phase 3.
If unclear, ask the user. Default to newsletter issue when they say "newsletter" or "issue"; default to web post when they say "article", "essay", "post", or "evergreen content".
Ghostwriting Workflow
When writing for someone else, voice matching comes before content. Read references/voice-matching.md for the full extraction process — it covers sample collection (transcripts > writing > media), voice marker extraction, building a voice guide (10-15 markers with examples), and iteration with the user.
Complete the voice guide and get user validation before proceeding to the Writing Workflow.
Writing Workflow
Phase 1 is mandatory — always ask the user the intake questions and wait for answers before writing anything. If the user already provided some context, extract what you can and ask only about missing pieces.
Phase 0: Voice calibration (own voice mode)
Skip this phase if ghostwriting (the Ghostwriting Workflow handles voice separately).
Ask the user for their existing Substack URL. If they have one, recent posts are a valuable source of tone markers — formality level, sentence rhythm, humor style, paragraph length, how they open and close, recurring phrases. Summarize the voice in 5-7 bullet points and confirm with the user before writing.
If they don't have an existing Substack, ask: "How do you want to sound? Casual and conversational, professional and authoritative, or something else?" Use their answer plus any other writing samples they can share.
Phase 1: Content planning (interview)
Stop and ask. Present the intake questions below to the user and wait for their answers. Do not skip this phase, do not infer silently, and do not start drafting until you have explicit answers or confirmation on every item.
- Topic: What's this about? If vague, ask what specific angle or story the reader should walk away with.
- Format: Newsletter issue (email-first) or web post (web-first)? See mode detection above.
- Audience: Who reads this? (developers, founders, marketers, general tech, niche community...) A newsletter for junior devs reads very differently than one for CTOs.
- Objective: What's the concrete goal?
- Grow subscribers (free or paid)?
- Drive signups/traffic to an external product (SaaS, course, tool)?
- Establish authority / thought leadership?
- Nurture existing subscribers toward a paid tier?
- Something else? The objective shapes the CTA, the hook angle, and where depth goes vs where the paywall or link sits.
- Context: Part of a series? What have recent posts covered?
- Length: Short (500-800 words), Standard (1000-1500), Deep dive (2000+)
If critical pieces are missing (especially topic, audience, objective, or format), ask and wait — don't guess. A wrong assumption wastes an entire draft.
If the user has Notes data (which Notes got engagement), use that to validate topic selection. Notes function as a cheap testing pipeline for long-form content.
Phase 2: Title and hook selection
Generate 5 title/subject line variants and 3 hook options (opening 2-3 sentences each). Present them together and ask the user to pick or remix before proceeding. Do not write the body until the user has validated a title and hook direction.
Title principles:
- Specificity beats vagueness
- Promise a clear benefit or reveal
- 6-10 words (readable on mobile and in search results)
- For dev audiences: technical keywords filter for the right audience; "How to" and numbers perform well; avoid urgency/scarcity tactics
Hook types — write 3 distinct hooks using different strategies (e.g. credibility, counter-narrative, curiosity, surprise, data). Each hook should be 2-3 sentences that could open the piece. Present them labeled (Hook A, Hook B, Hook C) with a brief note on the strategy used.
Newsletter issue — subject line + preview text:
- The subject line is the headline. The preview text (first ~90 chars of the email) is the subhead. Together they determine open rate.
- Preview text should complement, not repeat, the subject line.
Web post — SEO + discoverability:
- Keep the main title punchy for the feed. Use the separate SEO title field for a keyword-rich version (under 60 chars).
- Write a dedicated SEO description (150-160 chars) — don't rely on the subtitle fallback, it's usually too short.
- Suggest a URL slug: short (3-6 words), keyword-rich, no dates.
- Assign to a publication section if applicable.
- Read
references/web-post-formatting.md for detailed SEO guidance.
Wait for the user to choose a title and hook before moving to Phase 3.
Phase 3: Write the content
Using the chosen title and hook, write the full piece. The hook opens the article, then continue with:
- Hook (chosen from Phase 2)
- Context (1-2 paragraphs): Why this matters now. What prompted this.
- Body (bulk): The actual content. Structure depends on content type.
- Takeaway (1-2 sentences): The one thing the reader should remember.
- CTA (1-2 sentences): Ask for a specific action. Questions that invite replies are strongest (replies are an algorithm signal).
Newsletter issue formatting — read references/email-formatting.md for full rules:
- Paragraphs: 2-3 sentences max (email clients make long paragraphs feel like walls)
- Code blocks: < 10 lines (link to Gist for longer code)
- Images: sparingly (many email clients block them by default)
- TL;DR at top for issues > 1500 words
Web post formatting — read references/web-post-formatting.md for full rules:
- Paragraphs: 3-4 sentences acceptable (full-width web rendering is more forgiving)
- Longer code blocks OK (up to 30-40 lines with full syntax highlighting)
- Images and embeds render reliably — use more liberally
- Table of contents for posts > 2000 words
Shared formatting rules:
- Subheadings every 200-400 words. Bold key phrases so skimmers catch the argument.
- Descriptive anchor text on links, not "click here."