Magic Number

Definition. A sales-and-marketing efficiency ratio: net new ARR in a quarter divided by the prior quarter's S&M spend. Above ~1.0 suggests acquisition is efficient enough to invest harder; below ~0.75 says fix the engine before spending more.

@misc{shalvi_gtm_magic_number,
  author = {Singh, Shalvi},
  title  = {Magic Number — GTM World Model Glossary},
  year   = {2026},
  url     = {https://shalvisingh.com/gtm/glossary/magic-number}
}