Eightx Talk to a CFO

The Eightx Guides

The definitive guides
for ecom operators.

The questions every ecom founder asks before a board meeting — answered with benchmarks, not vibes.

How to Calculate Customer Acquisition Cost (CAC Formula, DTC Benchmarks, and the Marginal CAC Most Brands Miss)

Marketing & Acquisition

Customer Acquisition Cost

Formula, DTC benchmarks from 35 brands, the marginal CAC framework most agencies skip, the cohort-curve payback model, and a free calculator. The CAC reference.

Read the guide
How to Calculate Contribution Margin (Formula, the CM1/CM2/CM3 Ladder for DTC Brands, and a Calculator)

Margins & Unit Economics

Contribution Margin

CM1, CM2, CM3 broken down with DTC benchmarks. The version that drives max-CAC, payback, and channel-mix decisions. With the CM calculator.

Read the guide
Interim CFO Services: Cost, When to Hire, How to Choose (2026 Guide)

Finance & Operations

Interim CFO Services

Cost ($15-30K/month), 5 trigger events, vetting questions, first 72 hours playbook, the comparison to fractional, contract, and permanent CFO. By a fractional CFO firm.

Read the guide
LTV:CAC Ratio for DTC (Formula, Benchmarks, Why 3:1 Is Wrong)

Marketing & Acquisition

LTV:CAC Ratio

CM2:CAC formula, why the 3:1 SaaS rule is wrong for DTC, vertical + stage benchmarks, and the payback curve that matters more than the ratio. With CM-aware math.

Read the guide
Coming Soon

Finance & Operations

Fractional CFO Cost

What a fractional CFO actually costs in 2026, by engagement type, scope, and brand stage. Where the typical $7M-$50M DTC brand should land.

In production
Gross Margin Guide for DTC

Margins & Unit Economics

Gross Margin

Gross margin formula, DTC benchmarks by vertical, what goes above and below the line, and the practical differences between gross margin, CM1, and CM2 for ecom.

Read the guide
Return Rate Guide for DTC

Operations

Return Rate

2026 return-rate benchmarks by category, the CFO formula that ties returns to CM2, sellable recovery economics, and the levers that compress reverse-log spend.

Read the guide
Subscription Churn Guide for DTC

Retention & LTV

Subscription Churn

The 4 types of churn (voluntary, involuntary, active, passive), category benchmarks, and the 10 reduction levers that move the needle on DTC subscription retention.

Read the guide
Coming Soon

Cash & Runway

Burn Rate

Gross burn vs net burn. How to calculate runway off real cash, not pro-forma assumptions. The 13-week cash flow forecast every DTC founder should be running weekly.

In production
Inventory Management for D2C brands: working capital, frameworks, and cash playbook (2026)

Inventory & Cash

Inventory Management

The working capital math behind inventory in a DTC brand: DIO/turns, EOQ, safety stock + reorder points, ABC classification, and the cash-conversion playbook from 7-fig to 9-fig.

Read the guide
Fractional CFO for Beauty Brands: skincare, cosmetics, and haircare finance (2026)

Industry Guide

Fractional CFO for Beauty Brands

The beauty CFO playbook: shelf-life-aware inventory, the Sephora/Ulta vs DTC margin math, sampling and tester cost, formulation accounting, and exit prep. Plus the full beauty cluster.

Read the guide
Fractional CFO for Supplement Brands: nutraceutical, vitamin, and wellness finance (2026)

Industry Guide

Fractional CFO for Supplement Brands

The supplement CFO playbook: subscription LTV vs churn, cGMP and co-packer COGS, FDA/FTC compliance cost, expiry-aware inventory, Amazon vs DTC, and exit prep. Plus the full supplements cluster.

Read the guide
Fractional CFO for Apparel Brands: fashion, footwear, and accessories finance (2026)

Industry Guide

Fractional CFO for Apparel Brands

The apparel CFO playbook: size-curve inventory, markdown margin math, the true cost of returns, seasonal and wholesale cash, tariff-aware sourcing, and exit prep. Plus the full apparel cluster.

Read the guide
Fractional CFO for Food & Beverage Brands: CPG, grocery, and DTC finance (2026)

Industry Guide

Fractional CFO for Food & Beverage Brands

The food & bev CFO playbook: trade spend and slotting, the DTC/retail/distributor margin stack, co-manufacturing MOQs, shelf-life spoilage, and exit prep. Plus the full food & beverage cluster.

Read the guide

Want results like these?

Get Your Free
Profit Audit

30-minute call. We'll find at least one profit leak in your business—no strings attached.

Talk to a CFO