Magic Number for SaaS at Series B

Ehsan's Analysis

The SaaS Magic Number (net new ARR ÷ sales & marketing spend from the prior quarter) is the fastest way to evaluate go-to-market efficiency. Above 1.0 means every $1 spent generates $1+ of new ARR within a quarter — extremely efficient. 0.5-1.0 is healthy. Below 0.5 means you are spending $2+ to generate $1 of ARR — a sign of poor product-market fit, wrong ICP targeting, or overspending on low-converting channels. The nuance: magic number varies dramatically by go-to-market motion. Self-serve products should target 1.5+ (low sales cost). Inside sales should target 0.7-1.0. Field sales should target 0.5-0.7 (higher sales costs, larger deals). A field sales company with a 0.6 magic number is efficient. A self-serve company with a 0.6 magic number is broken. Always benchmark against your motion, not the category average. The magic number also has a time lag — spending in Q1 generates pipeline that closes in Q2 or Q3. Use a 2-quarter lag for enterprise and 1-quarter lag for self-serve.