B2B Marketing Unit Economics Assessment Suite

The B2B Marketing Unit Economics Assessment Suite by The Starr Conspiracy is a four-tool diagnostic for B2B marketing leaders who need to replace scattered spreadsheets with a defensible unit-economics measurement system covering CAC, LTV, payback period, and channel-level ROI. Teams that complete all four assessments typically surface a 15 to 30 percent CAC variance between blended and channel-isolated calculations, per OpenView Partners 2024 SaaS benchmark data.

We built this for GTM practitioners, not finance teams running generic startup math. The methodology accounts for the things B2B actually deals with: 9-month sales cycles, expansion revenue that doesn't show up for 18 months, multi-touch attribution across six-person buying committees, and channel CAC that gets buried inside blended averages until your board asks where the money went.

How the Suite Scores Your Unit Economics

Each tool exposes its formula and benchmark source publicly. Nothing about the methodology is gated. Only your personalized output, the scored report against peer segments, requires an email.

Tool 1: B2B CAC Calculator (Blended and Channel-Isolated)

Formula: CAC = (Total Sales and Marketing Spend in period) divided by (New Logos Acquired in period). The calculator runs this twice, once blended across all spend, once isolated per channel (paid search, paid social, content, events, outbound SDR, partner). Benchmark source: OpenView 2024 SaaS Benchmarks Report, segmented by ARR band ($1M to $10M, $10M to $50M, $50M+) and GTM motion (PLG, sales-led, hybrid).

Tool 2: LTV to CAC Ratio Scorecard (Logo LTV vs. Expansion LTV)

Formula: Logo LTV = (ARPA times Gross Margin) divided by Logo Churn Rate. Expansion LTV adds net revenue retention above 100 percent. The scorecard reports both ratios because they tell different stories. A 3:1 logo LTV to CAC with 130 percent NRR is a fundamentally different business than 3:1 with 95 percent NRR. Benchmark thresholds drawn from Bessemer Venture Partners State of the Cloud 2024.

Tool 3: CAC Payback Period Diagnostic (Sales-Cycle-Adjusted)

Formula: Payback Months = CAC divided by (ARPA times Gross Margin divided by 12), then add average sales cycle length in months. Most calculators skip the sales-cycle adjustment, which understates payback for enterprise motions by 4 to 8 months. The diagnostic flags whether your payback exceeds the SaaStr-published threshold of 12 months for SMB, 18 months for mid-market, and 24 months for enterprise.

Tool 4: Channel ROI Grader

Scores each acquisition channel on a 100-point rubric across four weighted dimensions: CAC efficiency versus blended (30 points), payback period versus segment benchmark (25 points), LTV to CAC ratio of acquired logos (25 points), and pipeline velocity contribution (20 points). Channels grade A through F. A grader is the only one of the four tools that produces a prioritized action list rather than a single metric.

What the Scores Mean

A (90-100): Defensible. Unit economics support aggressive reinvestment. Your board conversation is about scaling spend, not justifying it. Approximately 12 percent of B2B SaaS companies score here per Bessemer data.

B (75-89): Healthy. Unit economics are sound but one or two channels or segments drag the average. Optimization, not overhaul.

C (60-74): At Risk. Blended numbers look acceptable, but channel isolation reveals a subset of your spend is destroying value. This is where most companies live. Approximately 48 percent of mid-market B2B SaaS scores in this band.

D (45-59): Unprofitable Growth. LTV to CAC under 2:1 or payback exceeding segment threshold by 50 percent or more. You are buying revenue at a loss and the spreadsheet is hiding it.

F (under 45): Reset Required. The unit economics do not work at current spend levels. Cut, restructure, or change the GTM motion.

Methodology, Sources, and Limitations

Benchmark data is sourced from OpenView Partners 2024 SaaS Benchmarks Report, Bessemer Venture Partners State of the Cloud 2024, and SaaStr published payback period thresholds. Formula derivations follow the standard practitioner conventions documented by Wall Street Prep and Corporate Finance Institute, adjusted for B2B-specific complexity (sales-cycle-adjusted payback, expansion LTV, channel isolation) that finance-first calculators omit.

Limitations: the suite assumes you can attribute new logos to channels with reasonable accuracy. If your attribution is unreliable, the channel-isolated CAC and ROI grader will inherit that noise. The benchmarks reflect SaaS GTM motions and may not generalize cleanly to services, hardware, or hybrid models. Sample sizes for sub-segments below $1M ARR are thin and should be treated as directional.

The suite refreshes benchmark inputs on a 12-month cadence aligned with annual dataset releases. The Channel ROI Grader rubric is reviewed every 6 months.

How to Use the Results

Run all four tools in sequence. CAC first, because it is the input to everything else. LTV to CAC second, because the ratio tells you whether your acquisition is rational. Payback third, because it tells you when the cash returns. Channel ROI last, because it tells you where to cut and where to double down.

The output is designed for one specific conversation: the budget defense. Most marketing leaders walk into that conversation with a blended CAC number and a story. They walk out with a 10 percent haircut. The leaders who walk in with channel-isolated CAC, sales-cycle-adjusted payback, and a graded channel mix walk out with budget authority.

For methodology context, see our CAC payback period glossary entry and the B2B SaaS unit economics benchmarks hub. To operationalize the results, our marketing measurement framework shows how to wire these metrics into ongoing reporting.

The Bottom Line

Blended CAC is a lie of averages. Unit economics defended at the board level require channel isolation, expansion-adjusted LTV, sales-cycle-adjusted payback, and a graded channel mix. Run the four tools, get the scores, take the report to the budget conversation. If your scores land in the C or D band, the issue is not your spend level. It is which channels you are spending on, and this suite will tell you exactly which ones.

Ready to score your unit economics? Start with the CAC Calculator and work through the suite. The methodology is open. The personalized scorecard is yours when you finish.