Luca Barberis

Whose book is expanding?

№ 176 · Expansion revenue per CSM

01

Definition

MetricExpansion ARR generated from the CSM's existing book

Unit% of the CSM's starting book ARR (with $ per CSM per year as the secondary read)

Bar of net new expansion revenue generated per CSM. Pull upsell records by CSM owner. Tells you who is driving net growth beyond simple retention. Coach to the top performers' playbooks. Example: top CSM $480K expansion; bottom $80K (6x spread, investigate).

CSM
Customer success manager. Owner of retention and expansion for a book of accounts.
02

Benchmarks

Bottom 30%MedianTop 30%
5% or less of starting book (roughly $100K on a $2M book)12% to 13% of starting book (roughly $250K on a $2M book)20% or more of starting book (roughly $400K on a $2M book)

B2B SaaS, $1M to $100M ARR, gross expansion ARR (upsell, cross-sell, seat and usage growth, price increases) before contraction and churn, measured on the book present at period start over twelve months. · No published source measures expansion at the CSM level, so the benchmark is derived at company level and applied per book. The derivation is the NRR to GRR gap: Benchmarkit reports median NRR 101% against median GRR 88% for CY-2024, a 13 point gap, and SaaS Capital independently puts the average gap a little over 12 points with 8 to 20 points as the normal range. Those two put median gross expansion at 12% to 13% of starting ARR. Top30 and bottom30 are taken from the ends of SaaS Capital's normal range. Two caveats. First, this is gross expansion, not net: a CSM at 18% expansion and 20% contraction is destroying value, which is why this card must be read against card 177. Second, expansion attribution to CSM versus account management is contested, and ChurnZero's 2024 study found companies where account management owns expansion trend toward higher NRR, so a low number here may reflect ownership design rather than performance.

By category
CategoryBottom 30%MedianTop 30%
Company ARR under $15Munder 5%10% to 12% of book16%+ of book
Company ARR $15M to $50M6%13% of book20%+ of book
Company ARR above $50M8%16% to 18% of book25%+ of book
03

When it looks bad

One or two bars carry nearly all the expansion while the rest of the team sits near zero, which means expansion is coming from a handful of accounts that grew on their own rather than from a repeatable motion any CSM can run.

Six CSMs, $14.2M of managed ARR, $1.31M of gross expansion. One CSM accounts for $780K of it from a single seat expansion at one account. Strip that account out and team expansion is 4.1% of book, against a 12% to 13% median.

04

What to do about it

  • Instrument two or three usage triggers that precede an upgrade (seat utilisation above 85%, second business unit onboarding, API volume crossing a tier) and route them to the CSM as tasks with a deadline. Expansion is the cheapest ARR available: Benchmarkit puts expansion CAC ratio at $1.00 against $2.00 for new customer ARR, and Paddle's data puts upsell cost at $0.27 per $1 of yearly revenue versus $1.13 for a new customer.
  • Fix packaging before coaching. A narrow GRR to NRR gap of under 5 points, which SaaS Capital found in fewer than 10% of companies, almost always means there is nothing to upsell into rather than a CSM who will not ask. Add a second tier or a usage-linked line before running an expansion play.
  • Decide explicitly who owns the expansion transaction and comp them for it. ChurnZero's 2024 study found only 35% of CS teams own expansion in the highest NRR band, and companies where account management owns it trend higher, so splitting the motion is a defensible design rather than a failure.
  • Put contractual price escalators in renewals. They are the one expansion lever that does not depend on the customer buying more, and SaaS Capital flags inflation adjusters as widely neglected after the low-inflation decade.
05

Sources

  1. Benchmarkit (with Pavilion)2025 B2B SaaS Performance Metrics Benchmarks · 2025 · n=583 private B2B SaaS companies, CY-2024 actuals; metric-level samples smaller (NRR n=228, GRR n=225, expansion ARR n=81, expansion CAC n=21) Median NRR 101% (down from 105% in CY-21, 103% in CY-22). Median GRR 88%, down from 90% over three years. Expansion ARR is 40% of total new ARR at median, 58% at $50M to $100M ARR, 67% above $100M. Expansion CAC ratio $1.00 versus new customer CAC ratio $2.00. Subscription gross margin 81% median. GRR and NRR both rise as ACV rises. 5242563.fs1.hubspotusercontent-na1.net ↗
  2. SaaS CapitalExamining the Gap Between Gross Revenue Retention and Net Revenue Retention · 2023 · annual private B2B SaaS survey population, gap histogram across respondents Average GRR to NRR gap is a little over 12 percentage points. A range of 8 to 20 points is normal. Fewer than 10% of companies report a gap under 5 points, which signals weak upsell and cross-sell. Gaps above 30 points are rare and usually indicate a one-off or a concentration problem. saas-capital.com ↗
  3. ChartMogulThe SaaS Retention Report: The New Normal For SaaS · 2024 · n=2,500+ SaaS businesses, aggregated anonymised billing data, H1 2021 to H1 2024 Expansion drives up to 40% of growth for companies at $15M to $30M+ ARR, versus 30% in early 2021. Even the top quartile at $15M to $30M+ ARR failed to reach 100% NRR in 2024. Companies at or above 100% NRR draw over half of added revenue from expansion; companies below 60% NRR draw 70% from new business and 15% from expansion. New customers expand most during year one as they ramp usage, and churn tends to rise in year two. Median churn in the low NRR bucket is 7%, double that of companies at or above 100% NRR. chartmogul.com ↗
  4. SaaS CapitalWhat is a Good Retention Rate for a Private SaaS Company in 2025? · 2025 · n=1,000+ private B2B SaaS companies, 14th annual survey, ARR above $1M Companies with ACV between $25,000 and $50,000 report median NRR of 102%, top quartile 111%, bottom quartile 97%. NRR correlates positively with ACV. Companies with the very highest ACVs report the highest GRR. NRR defined as December 2024 MRR from customers present in December 2023, divided by total December 2023 MRR. saas-capital.com ↗
  5. ChurnZeroCustomer Success Leadership Study 2024 · 2024 · annual survey of customer success leaders Within the highest self-reported NRR band only 35% of CS teams own expansion; companies where account management owns expansion trend toward higher NRR. Differences in ACV and CSM load across NRR bands were moderate but statistically reliable. Reports frequency of CSM to customer in-person meetings for 2023 and 2024. churnzero.com ↗
  6. Paddle (ProfitWell data)30%+ of your revenue should be expansion revenue. You're likely at 10% · 2022 · ProfitWell subscription dataset plus Pacific Crest survey series Acquiring a new customer costs $1.13 for every $1 of yearly revenue, so payback runs past the first year. Upsell customers cost $0.27 for every $1 of yearly revenue, recovering cost within a single quarter. Faster-growing companies take more of their new ACV from upsells. paddle.com ↗
  7. KeyBanc Capital Markets and Sapphire Ventures16th Annual Private Company SaaS Survey · 2025 · private SaaS companies, published November 2025 Gross retention is expected to approach the 90% threshold after declining to 86% in 2023. Net retention has remained above 100% through the same period with modest improvement expected. YoY ARR growth expected to accelerate from 15% in 2024 to 20% in 2025. sapphireventures.com ↗
  8. ChartMogulSaaS Reports and Benchmarks hub · 2025 · n=2,500+ SaaS businesses across the report series Best-in-class net revenue retention sits in the 110% to 120% range. For B2B SaaS selling to mid-market and enterprise, best-in-class is 115% to 125%. Companies above 100% NRR grow 1.5x to 3x faster than peers. B2C businesses rarely exceed 85% gross retention. chartmogul.com ↗
  9. GainsightCustomer Success Team Planning and Cost Benchmarks · 2016 · survey of attendees at Gainsight's Chief Customer Officer Summit Median ARR managed is $2M to $5M for an enterprise CSM (10 to 50 customers) and for a mid-market CSM (100 to 250 customers), and $1M to $2M for an SMB CSM (100 to 250 customers, 37% above 250). CS team cost: above $100M ARR the bulk sit at 10% of ARR or less and 39% below 5%; between $10M and $100M ARR, under 15% is within benchmark; below $10M ARR, under 20% is within benchmark. gainsight.com ↗