Why CAC is Usually Irrelevant in Early-Stage SaaS Companies

Jason Lemkin argues that Customer Acquisition Cost (CAC) is a misunderstood and largely irrelevant metric for early-stage B2B SaaS companies, particularly those under $2M ARR, because early customers are typically high-affinity users acquired through word-of-mouth and brand rather than paid marketing. The article contrasts this with B2C and services businesses where CAC is critical, and advises founders to focus on managing spend relative to growth rather than optimizing CAC in early stages.