F · Unit economicsExternally proven

Magic Number

The magic number measures how much new ARR one unit of sales and marketing spend generates. Above 0.75 the go-to-market machine is considered efficient enough to accelerate; below that, fix the model first.

When you need this method

You face the decision to raise sales and marketing budget significantly but do not know whether the machine converts additional money efficiently. More budget on an inefficient motion only accelerates capital burn. You need a normalized metric that says: step on the gas or repair first.

Approach

  1. 1Determine net new ARR won in the quarter (annualized).
  2. 2Divide it by the prior quarter's sales and marketing spend.
  3. 3Read the result against the thresholds: above 0.75 is efficient, around 1.0 corresponds to roughly a twelve-month S&M payback, below 0.5 the machine is stalling.
  4. 4Above the threshold: increase budget and watch whether the metric holds.
  5. 5Below it: look for causes in positioning, target segment or sales process before spending more.

Typical application

A typical case: a scale-up with an ambitious growth plan wants to double its sales budget. The magic number has sat well below the efficiency threshold for two quarters, which leadership had dismissed as a ramp-up phase. Instead of doubling the budget, the team first analyzes where the chain breaks and finds unclear positioning in the new target segment. Only after fixing it, visible in a rising magic number, is the budget increased step by step.

Limits and counter-indications

The metric is volatile quarter to quarter, especially with few large deals; read the trend, not a single value. It measures new-business efficiency, not retention or margin; a good value can coexist with weak retention. Long enterprise cycles spread spend and return across several quarters.

How to measure impact

Magic number per quarter (net new annualized ARR divided by prior-quarter S&M spend), trended over several quarters.

Related methods

Sources

  1. 1.SaaS Metrics: A History of the Magic Number, Scale Venture Partners (opens in a new tab) · Scale Venture Partners · o. J. · investment, consulting or analyst firmBelegt Herkunft und Zweck der Kennzahl (2005 von Rory O'Driscoll bei Scale geprägt) und nennt 0,7 als gesunde Basislinie für die Vertriebseffizienz eines Softwaregeschäfts.
  2. 2.Magic Number Math, Rory O'Driscoll, Scale Venture Partners (opens in a new tab) · Scale Venture Partners · 2010 · investment, consulting or analyst firmTrägt die Rechenvorschrift (annualisierte Umsatzveränderung zweier Quartale geteilt durch den Vertriebs- und Marketingaufwand des Vorquartals) und die Schwellen über 1,0, 0,5 bis 1,0 und unter 0,5.

Origin: Skok/Bessemer

Last reviewed: 2026-07-25 by Dr. Oliver Gausmann

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