ecommerce-advisor

name	ecommerce-advisor
description	Strategic advisory for e-commerce founders on unit economics, fulfillment models, payments, and channel strategy. Use when evaluating an ecommerce idea or modeling unit economics, or mentioning DTC, Shopify, Amazon, 3PL, or CAC.
license	MIT + Commons Clause
metadata	{"version":"1.0.0","author":"borghei","category":"vertical-advisors","domain":"ecommerce","updated":"2026-05-04T00:00:00.000Z","python-tools":"ecom_unit_economics_calculator.py","tech-stack":"ecommerce, retail"}

E-commerce Advisor

Strategic frameworks for e-commerce founders, operators, and brand builders. Most ecommerce decisions are unit-economics decisions — knowing the math is the difference between a brand that compounds and one that subsidizes itself out of existence.

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Keywords

ecommerce, e-commerce, DTC, direct-to-consumer, Shopify, Amazon, retail, wholesale, 3PL, fulfillment, dropship, unit economics, contribution margin, CAC, AOV, LTV, returns, refunds, payment processing, interchange

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Clarify First

Before building the model, confirm these inputs. If any is unknown or vague, ASK — do not assume:

• Single channel or blended — model each channel (DTC, Amazon, wholesale) separately; a blended model hides an unprofitable channel and makes contribution margin meaningless
• AOV and COGS — average order value and landed cost of goods (drives gross margin, the top line of the model)
• Returns/refund rate — returns eat margin twice (the sale plus reverse logistics), so this swings contribution margin
• CAC basis — true paid/blended CAC and what ad spend is counted (drives CAC payback period and break-even repeat rate)

Stop rule: ask only the 2-3 that most change the output. If the user says "just draft it," proceed and list your assumptions at the top of the model.

Quick Start

python scripts/ecom_unit_economics_calculator.py model.json

Calculates gross margin, contribution margin, CAC payback, and per-order profit from a structured input file.

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Core Workflows

Workflow 1: Unit Economics Model

1. Build a JSON config: COGS, fulfillment cost, payment processing %, returns %, ad spend %, AOV
2. Run calculator: python scripts/ecom_unit_economics_calculator.py model.json
3. Identify the marginal cost line items eating most of the margin
4. Decide: cut costs, raise price, change channel mix, or kill the SKU

Time Estimate: 2-4 weeks for first robust model.

Workflow 2: Fulfillment Strategy

1. Read references/fulfillment_models.md
2. Score each model (DTC self-fulfilled, 3PL, Amazon FBA, dropship, retail) for your stage and SKU profile
3. Migrate fulfillment as you scale — most brands change models 2-3 times in their first 3 years

Time Estimate: 4-8 weeks per major fulfillment transition.

Workflow 3: Channel Strategy

1. Read references/channel_strategy.md
2. Decide channel mix: DTC site, Amazon, wholesale, retail, marketplace
3. Each channel has distinct unit economics — model them separately, never blend
4. Sequence: most brands start DTC, add Amazon, add wholesale / retail

Time Estimate: Continuous, with major decisions every 6-12 months.

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Tools

ecom_unit_economics_calculator.py

Models per-order, per-month, and CAC-payback economics from a structured input.

python scripts/ecom_unit_economics_calculator.py model.json
python scripts/ecom_unit_economics_calculator.py model.json --json

Input model schema in the script's docstring; example in assets/unit_economics_template.json.

Outputs:

• Gross margin (% and absolute)
• Contribution margin (after marginal CAC)
• CAC payback period (months)
• Break-even repeat rate

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Reference Guides

• references/fulfillment_models.md — DTC self, 3PL, FBA, dropship, retail — when each fits
• references/channel_strategy.md — DTC site, Amazon, wholesale, retail — economics per channel

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Templates

• assets/unit_economics_template.json — Input file for the calculator with example values

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Best Practices

• Model channels separately. A blended LTV across DTC and Amazon hides the fact that Amazon may be unprofitable.
• Returns and refunds compound. A 15% return rate eats into margin twice — once on the initial sale, once on the reverse logistics.
• Plan for inventory. Working capital tied up in inventory is the #1 cash-flow killer for product brands.
• Don't fall in love with revenue. $10M revenue at 5% contribution margin is worse than $3M revenue at 30% contribution margin.
• Be honest about CAC. Most DTC brands subsidize CAC and call it growth. CAC payback under 6 months is the bar.