“If your TAM is really small or your serviceable addressable market is really small, you might want to weight your investment in ARPU more than you do subscription growth. You might say okay really we might reach saturation a little bit quicker than we originally thought — we should focus on going ARPU.”

Small SAM → invest in ARPU before subscriber growth

Niche SAM dictates the playbook. If you'll saturate subscriber acquisition fast, the lever becomes pricing, tiers, and add-ons — not more signups. Big TAM lets you optimize for volume; small SAM forces you to optimize for value per user.