MRR is the monthly-resolution version of ARR — the total value of active recurring subscriptions in a given month. It is the most frequently monitored revenue metric for early-stage SaaS companies because it updates monthly and gives a real-time view of business health. The MRR movement in any given month can be decomposed into: new MRR (from new customers), expansion MRR (upsells or cross-sells to existing customers), contraction MRR (downgrades), and churned MRR (cancelled customers).
The difference between new MRR and the sum of contraction and churned MRR is net new MRR — the number that determines whether the business is growing or shrinking. A company with $80K new MRR but $90K in churned and contracted MRR has a negative net new MRR of -$10K, which means it is declining in absolute terms despite acquiring new customers. This pattern is called "leaky bucket" growth and is one of the most common early-stage SaaS failure modes.
For AI-scored pitch decks, MRR is the most important single traction metric at seed stage. A company with clearly presented, time-series MRR data — ideally showing the last 6 to 12 months of month-on-month growth — receives a meaningfully higher confidence score than one that presents a static ARR figure without historical context.