Your beachhead market is the single, highly-specific customer segment you will target first — and dominate — before expanding.

Think of D-Day: you don't invade all of Europe at once. You land at one beach, secure it completely, then advance.

Too broad: "Small businesses" or "tech startups"

Good: "Solo bootstrapped SaaS founders in the US with $5K–$50K MRR who do their own customer support."

A moat is your sustainable competitive advantage — the reason why, once you win a customer, a competitor can't easily take them away.

The term comes from Warren Buffett: a castle (your business) is only worth defending if it has a moat around it.

Examples of moats:

Network Effects: The product gets more valuable as more people use it (e.g. WhatsApp, Airbnb).

Technology: Proprietary tech, patents, or a model that's hard to replicate.

Unique Insight: You understand a problem or market in a way competitors don't — yet.

Weak answer: "We'll move fast" or "better UX."

Strong answer: "Every new supplier on our platform makes it cheaper and faster for every buyer — neither side will leave."