GRR measures the percentage of recurring revenue retained from existing customers — excluding any expansion. Where NRR can exceed 100% via upsell, GRR is capped at 100% because it only counts losses: churn and contraction.
GRR is a purer signal of customer satisfaction than NRR. A company with high NRR but low GRR is papering over high churn with aggressive expansion. SaaS investors look at both together: GRR below 80% in enterprise or below 70% in SMB typically indicates a product or fit problem that upsell cannot fix.