Report NRR alone and you can hide a serious leak. The fix is to read it next to gross revenue retention (GRR), which counts only the losses — starting revenue minus downgrades and churn, with expansion stripped out entirely.
GRR = (Starting MRR − Contraction − Churn) ÷ Starting MRR × 100
GRR can never exceed 100% by definition. It is the floor — the honest measure of how leaky your bucket is before any upsell papers over the holes. NRR can sail past 100% because expansion is added back in.
The gap between them tells the real story. A company at 120% NRR and 95% GRR is a healthy machine: it loses almost nothing and its winners expand hard. A company at 105% NRR and 80% GRR is a treadmill — hosing expansion revenue from a minority of accounts to mask a base that is haemorrhaging. Same headline NRR, completely different business. As the diagnostic goes: 95% logo retention sitting on 85% net revenue retention means customers are staying but spending less, a contraction problem dressed as a retention success.
The discipline is: never quote NRR without GRR beside it. GRR audits your product and your customer retention motion; NRR audits your expansion engine. Both belong on the same dashboard.
For a lean founder running AI agents across the customer base, GRR is also the metric that tells you where to point your retention agent first. If GRR is below 90% and NRR is above 100%, the expansion motion is masking a product or onboarding problem — and the agent should be triaging at-risk accounts, not hunting upsell triggers. Fix the floor before you raise the ceiling.