Expanding an existing account costs a fraction of winning a new one. In a nine to twelve month cycle, a new customer requires months of business development, plant visits, trial orders, quality audits, vendor onboarding, and often a discounted first year. An existing account at 25 percent share requires a conversation with someone who already returns your calls. For companies with long-tenured customers, the addressable revenue inside the top 20 accounts frequently exceeds the entire prospect list.