Erosion

You're seeing Erosion when a competitor's market share declines by one or two points every quarter — not dramatically, but persistently. No single event explains it; the cumulative effect is devastating.

You're seeing Erosion when an organisation loses its best people gradually — one departure per month — and each loss slightly degrades institutional knowledge, culture, and capability until the compound effect is visible.

Monitor your key metrics for slow, consistent declines — they're more dangerous than sudden drops because they're easier to ignore. When you spot erosion, treat it as urgent. And when competing, remember that small, sustained advantages compound into dominant positions over time.

Buffett has always understood erosion — both as a weapon and a threat. He invests in companies with durable competitive advantages precisely because he knows that without a moat, erosion is inevitable: competitors gradually chip away at margins, market share, and pricing power. His famous line — "the most important thing is the durability of the moat" — is a statement about erosion resistance. Founders can apply this by building businesses that can withstand sustained competitive pressure and by recognising that their own advantages erode over time without reinvestment. Equally, Buffett's approach to competition is erosive: Berkshire's subsidiaries use scale, cost advantages, and patience to steadily take share from weaker competitors. Erosion rewards the patient.