Expansion Revenue is additional revenue generated from existing customers through upsells (moving to a higher tier or adding seats), cross-sells (adding a new product or module), or usage-based growth. It is the primary driver of NRR above 100% and is often the highest-margin revenue a SaaS company generates because the cost of sales is significantly lower than acquiring a new logo. The most effective expansion motions are driven by customer success teams who help customers achieve outcomes and identify natural triggers for expansion.