Join the waitlist

Books
Videos

How he makes $250K per month from a simple app (Letterly Breakdown)

How he makes $250K per month from a simple app (Letterly Breakdown)

Published: 24 November 2025

Watch on YouTube

The operating system for an autonomous business.

Choices that keep coming back become the way you work: the SOPs write themselves.

Join the waitlist

Product

Overview
How it works
12-week cycles
AI employees
Agents
Pricing

Factories

Brand
Client acquisition
Value delivery
Value creation
People
Finance

Solutions

Head of growth
Digital marketer
SaaS
Agencies
All audiences

Library

Playbooks
Tools
Books
Glossary
Docs
Search

Company

About
Customers
Integrators
Contact
Brand kit

© Solid Growth. Made in the Netherlands.

Privacy policy Platform terms Consultancy terms Affiliate disclosure Cookie policy Disclaimer

The six factories and their four layers

Brand
They get to know and trust you, before they are buying
Client acquisition
They buy, from the moment someone is buying to the signature
Value delivery
They get the result and stay, from the signature to renewal
Value creation
What we make, whatever its type: software, a service or a course
People
Employees, fractionals, freelancers and AI agents, counted as one workforce
Finance
The money and the rules

Popular playbooks

Outbound
Grow existing accounts
Keep customers longer
Master your workweek
Financial statements
Website

Tool categories

Tech stack
Outbound
HR
Bookkeeping
CRM
Content marketing

Popular tools

Airtable
Lemlist
Confluence
Xero
Salesforce
Jasper

Top comparisons

Airtable vs Coda
Airtable vs Google Workspace
Coda vs Google Workspace
Instantly vs Lemlist
Lemlist vs Reply.io
Kanbox vs Lemlist

Glossary

A/B testing
Back-office Automation
CAC Payback Period
Data Hygiene
Economic buyer
Feature flag

Books

$100M Offers
Customer Success
Continuous Discovery Habits
Atomic Habits
$100M Leads
Demand-Side Sales 101