A CSM is the primary post-sales relationship owner for assigned accounts. Responsibilities span onboarding, adoption, value realization, executive business reviews, expansion identification, and renewal negotiation. CSMs are typically segmented by ACV or company size - strategic accounts have named CSMs; SMB accounts use pooled or digital-led CSM models. Industry benchmark: 1 CSM per $5M-$10M ARR (enterprise) up to 1 per $1M (SMB / pooled).
See how public B2B SaaS companies disclose this metric, with full historical time series.