GRR measures the percentage of revenue retained from existing customers over a period, counting only churn and contraction — it excludes expansion revenue. Because expansion cannot compensate for lost revenue in GRR, it is capped at 100% and shows the raw stickiness of the product. GRR is a cleaner signal of churn risk than NRR and is particularly important for investors evaluating whether a business can grow revenue through expansion or is just papering over churn.