In this episode of The Product Handbook, we unpack Product-Market Fit — and go further with Brian Balfour’s Four Fits framework for building sustainable growth.

You’ll learn:

• Why Product-Market Fit is only the first step, and how it fuels (or stalls) growth
• The Four Fits: Market–Product, Product–Channel, Channel–Model, and Model–Market — and what alignment looks like in each
• How ARPU shapes which channels and business models actually make sense for your product
• Practical tools like Test Cards and Learning Cards to validate assumptions and measure progress

If you’ve ever wondered why some startups hit a wall after finding Product-Market Fit, this episode shows how aligning across all Four Fits is the real key to scaling.