100x your newsletter's organic growth.
Grow while you write: we post, schedule, and amplify your content across X & LinkedIn to bring readers straight to you.
The 5 Mistakes Every SaaS Founder Makes
I've mentored 200+ founders. Here's what kills most startups before they even get to PMF...
I've worked with 200+ SaaS founders.
The #1 thing that kills startups?
It's not the product.
It's not the market.
It's building without talking to users...
After mentoring 200+ founders, here are the 5 mistakes that kill SaaS startups:
1. Building without user interviews
2. Scaling before PMF
3. Ignoring churn signals...
45.8K
Impressions
+247
Followers
1.2K
Clicks
4.7%
Engagement
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See Letterly in action
Watch how newsletter creators use Letterly to 10x their social presence
Everything newsletter creators need to grow
Analytics, AI content, and automation - all in one place
Track everything that drives growth
Monitor newsletter performance, social engagement, and CTA conversions all in one unified dashboard. Know exactly what's working and where your subscribers come from.
Newsletter + Social Analytics Combined
See subscribers, open rates, impressions, and engagement across all platforms in one place
Smart CTA Tracking
Track every link click with branded short URLs and see which content drives conversions
Growth Insights
Understand your audience with growth charts, conversion funnels, and performance trends
Performance Overview
Last 30 days2,847
45.2K
1,247
187
Marc Lou
SaaS entrepreneur persona
Marc Lou
Indie Maker • 2h ago
Just shipped a new feature in 48 hours that took my competitor 6 months. The secret? Move fast, stay focused, and don't overthink it.
Here's what I learned about rapid product development... 👇
Content that sounds like YOU
Clone your voice or model any creator's style. Every post feels authentic, on-brand, and genuinely human - not robotic AI content.
Voice Cloning from Your Profile
Analyze your LinkedIn or X posts to capture your unique tone, style, and personality
Model Other Creators
Analyze any creator's LinkedIn or X profile to capture and replicate their writing style and voice
Consistent Brand Voice
Maintain your unique style across every platform automatically - no more rewriting for different channels
Copilot creates & schedules your entire week
Your AI Copilot automatically generates weekly content plans, schedules posts at optimal times, and publishes directly to LinkedIn and X. Zero manual work required.
Auto-Generated Weekly Plans
Copilot creates a complete content calendar from your newsletter, balanced across platforms
Optimal Timing
Automatically schedule posts when your audience is most active for maximum engagement
Direct Publishing
Posts publish directly from Letterly to LinkedIn and X - no copy-pasting or third-party tools
Content Calendar
Upcoming This Week
5 lessons from scaling to $100K MRR...
Tomorrow, 9:00 AM
The biggest mistake I see new founders...
Friday, 3:00 PM
How It Works
From newsletter to social growth in minutes
Add Your Newsletter Content
Paste your newsletter URL or copy your content directly into Letterly. No complex integrations required.
- Paste any newsletter URL
- Or copy-paste your content
- Works with any newsletter platform
Transform Content
AI PoweredYour Newsletter
"The 5 Mistakes Every SaaS Founder Makes (And How to Avoid Them)"
Generated 8 posts for LinkedIn & X
AI Transforms Your Content
Clone the writing style of any LinkedIn or X profile. Our AI analyzes their tone, structure, and expressions to create posts that sound authentic.
- Clone any X or LinkedIn writing style
- Multiple attitudes & thread styles
- Creative or strict mode control
- Custom CTAs & optimized formatting
Schedule & Post Automatically
Review, edit, and schedule your content calendar. Posts go live automatically at optimal times.
- Direct posting to LinkedIn & X
- Optimal timing suggestions
- Performance tracking & analytics
Content Calendar
Today's Schedule
Loved by creators worldwide
Join newsletter creators who trust Letterly to grow their audience
"It's like hiring a junior content manager who does 90% of the work, but you always get the final say."
ChatGPT
LLM
"You're a fucking genius and I love you."
Affectionate-Turn495
Reddit User
"The service you provide is a great idea. I've always thought i'd love to help our SEO clients turn the articles we create for them into social posts as well."
Rob Hoffman
CEO @ Contact.so | Mentions.so | Kleo.so
"Letterly turned my newsletter into a real growth engine. I went from posting randomly to having a full weekly plan that actually performs."
Letterly User
Newsletter Creator
"I used to spend hours rewriting my newsletter for socials. Now it takes me 2 minutes. The posts feel like me, not AI, and engagement doubled."
Letterly User
Content Creator
"It's like hiring a junior content manager who does 90% of the work, but you always get the final say."
ChatGPT
LLM
"You're a fucking genius and I love you."
Affectionate-Turn495
Reddit User
"The service you provide is a great idea. I've always thought i'd love to help our SEO clients turn the articles we create for them into social posts as well."
Rob Hoffman
CEO @ Contact.so | Mentions.so | Kleo.so
"Letterly turned my newsletter into a real growth engine. I went from posting randomly to having a full weekly plan that actually performs."
Letterly User
Newsletter Creator
"I used to spend hours rewriting my newsletter for socials. Now it takes me 2 minutes. The posts feel like me, not AI, and engagement doubled."
Letterly User
Content Creator
"I used to spend hours rewriting my newsletter for socials. Now it takes me 2 minutes. The posts feel like me, not AI, and engagement doubled."
Letterly User
Content Creator
"The persona feature is insane. I imported my LinkedIn posts and Letterly pretty much cloned my voice. Zero AI detection issues."
Tight_Replacement796
Reddit User
"My impressions on X jumped 140% in the first week. I'm finally consistent because Letterly does the scheduling for me."
Letterly User
Social Media Manager
"I stopped worrying about when to post. Copilot handles the timing, the drafts, everything. I just approve and go."
Party_Major5753
Reddit User
"As a solo creator, Letterly feels like having a content team. Newsletter to social content to scheduling to analytics. All in one place."
Letterly User
Solo Creator
"I used to spend hours rewriting my newsletter for socials. Now it takes me 2 minutes. The posts feel like me, not AI, and engagement doubled."
Letterly User
Content Creator
"The persona feature is insane. I imported my LinkedIn posts and Letterly pretty much cloned my voice. Zero AI detection issues."
Tight_Replacement796
Reddit User
"My impressions on X jumped 140% in the first week. I'm finally consistent because Letterly does the scheduling for me."
Letterly User
Social Media Manager
"I stopped worrying about when to post. Copilot handles the timing, the drafts, everything. I just approve and go."
Party_Major5753
Reddit User
"As a solo creator, Letterly feels like having a content team. Newsletter to social content to scheduling to analytics. All in one place."
Letterly User
Solo Creator
Simple, transparent pricing
Choose the plan that fits your content creation needs
Features
Standard
For Weekly Newsletter Owners
Pro
For Daily Newsletter Owners
Letterly vs. the alternatives
Stop wasting time or money. See how Letterly stacks up against organic growth and paid ads.
| Metric | Organic Growth | Paid Ads | 98% cheaper vs organic96% cheaper vs ads Letterly Pro |
|---|---|---|---|
| Cost per month | 50+ hrs of time | $300+ | $12.99 |
| Estimated clicks | ~250 | ~300 | ~500 |
| Subscribers gained | ~50 | ~60 | ~100 |
| Cost per subscriber | time | ~$5 | ~$0.12 |
| Sustainability | Slow & tiring | Stops when you stop paying | Compounding organic growth |
Calculate your own ROI
Adjust your ad spend and time investment to see how much more you save with Letterly
Organic Growth
Subscribers gained
80
Monthly cost
$600.00
Cost per subscriber
$7.50
Paid Ads
Subscribers gained
60
Monthly cost
$300.00
Cost per subscriber
$5.00
Letterly Pro
Subscribers gained
100
Monthly cost
$12.99
Cost per subscriber
$0.13
98% cheaper
than manual organic growth
96% cheaper
than paid ads
The complete newsletter growth platform
Built for newsletter creators who want to grow organically
What is Letterly?
Letterly is an AI-powered platform designed specifically for newsletter creators who want to grow their audience organically through social media. We transform your existing newsletter content into engaging, platform-optimized posts for LinkedIn and X (Twitter), maintaining your unique voice while maximizing reach and engagement.
Unlike generic social media schedulers or basic content repurposing tools, Letterly combines advanced AI voice cloning, direct platform publishing, comprehensive analytics, and intelligent automation to create a complete growth ecosystem for newsletter creators.
Who is Letterly for?
Newsletter creators, content marketers, solo entrepreneurs, and thought leaders who publish regular newsletters on platforms like Substack, Beehiiv, ConvertKit, Ghost, or Mailchimp and want to amplify their reach through LinkedIn and X without spending hours manually adapting content.
What problems does Letterly solve?
Saves 10+ hours per week by eliminating manual content adaptation, maintains consistent posting schedules, prevents writer's block with AI assistance, tracks performance across all platforms in one place, and grows your newsletter organically by driving social traffic to your content.
Key Capabilities
Everything you need to grow your newsletter through social media
AI Voice Cloning
Analyzes LinkedIn or X profiles to replicate any writing style with high accuracy
Content Transformation
Converts long-form newsletters into optimized posts, threads, and carousels
Direct Publishing
Posts directly to LinkedIn and X without third-party integrations or manual copy-pasting
Smart Scheduling
AI-powered Copilot generates weekly content calendars and schedules posts at optimal times
Unified Analytics
Combines newsletter metrics, social performance, and CTA tracking in one dashboard
Link Tracking
Branded short URLs track every click to measure content effectiveness
Integration Compatibility: Works with all newsletter platforms including Substack, Beehiiv, ConvertKit, Ghost, Mailchimp, and more. Simply paste a URL or copy-paste your content - no complex setup required.
Getting Started: Free trial available. Create an account, add your first newsletter, and see AI-generated social posts in minutes. No credit card required for trial.
Everything you need to know
Common questions about Letterly, features, and pricing
Still have questions? We're here to help.
Get started with LetterlyReady to transform your newsletter into a growth engine?
Join creators who are building engaged communities while saving hours every week. No credit card required.