Learn the simple math behind viral growth and why k>1 means exponential expansion
Part of Growth Tactics That Actually Work
Educational content slides
Simple question: How many new users does each existing user bring?
This number is called the viral coefficient or k-factor. It's the single most important number in viral growth.
If k > 1, you grow exponentially. If k < 1, you eventually plateau. That's it. That's the entire game.
Test your understanding with this quiz.
Your app has 1,000 users. Each user invites 8 friends on average. 10% of invited friends sign up. What's your k-factor and what does it mean?
Complete this exercise and get AI-powered feedback.
Understanding the math helps you see what levers to pull.
Remember: k = (invites per user) × (conversion rate)
Goal: Get above 1.0 for exponential growth