Expansion revenue
New recurring revenue from existing customers — upgrades, added products, seat or usage growth — the component that can push net revenue retention above 100%.
Expansion revenue is growth that comes from the customer base you already serve: plan upgrades, additional products or modules, more seats, higher usage tiers. It is the "expansion" term in the net revenue retention formula, and it is what allows a company's existing base to grow revenue even before any new logo is signed. It is also, almost universally, the cheapest revenue available — the relationship, the trust, and the deployment already exist.
The difference between companies with strong and weak expansion is rarely the product; it is whether expansion is a system or an accident. Accidental expansion waits for the customer to volunteer. Systematic expansion watches for readiness signals — deepening adoption, approaching plan limits, healthy engagement, new teams appearing — qualifies them, and routes a concrete opportunity with its evidence to whoever runs the commercial conversation. That last step matters most: expansion signals that CS notices but sales never hears about are the most expensive Slack messages in SaaS.