Land-and-expand starts with a small initial sale, one team, one use case, then expands into the rest of the organization over time. The 'land' is often a low-touch, self-serve, or free-trial motion; the 'expand' is a sales-led upsell into adjacent teams, premium tiers, or new product lines.
The model produces excellent net revenue retention when expansion is structural, and dangerous concentration risk when a small number of accounts drive most of the ARR.