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Business Model Viability with Payment Costs

Your business model might not survive payment costs. A product with 25% gross margin and 4% payment costs leaves 21% to cover marketing, ops, and profit. Add 1% chargebacks and you're at 20%. This page helps you validate viability BEFORE launch.

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The Question This Answers​

"Can I actually make money after payment costs?"

Most SMBs calculate:

  • Product cost: $30
  • Sell for: $50
  • Margin: 40% = $20 profit
  • Conclusion: Viable!

But they forget:

  • Payment fees: $1.95 (3.9%)
  • Chargebacks: $0.50/order average (0.5% ratio × $100 true cost)
  • Fraud decline recovery: $0.25/order
  • Real profit: $17.30 (34.6% net margin)

Add marketing/CAC ($15/customer) and net profit is $2.30 (4.6%).

One spike in chargebacks to 1.5% and you're losing money.

Unit Economics Calculator​

Step 1: Base Economics​

Your NumbersCalculation
Selling price: $______A
Product cost: $______B (COGS)
Gross margin: $______C = A - B
Gross margin %: ___%C / A

Step 2: Payment Costs Per Transaction​

CostCalculationAmount
Processing feeA × rate + fixed$____
Chargeback costCB ratio × true CB cost$____
Fraud false positiveFP rate × A$____
Total payment costSum above$____

Step 3: Net Margin After Payments​

MetricCalculation
Net margin after paymentsC - payment costs
Net margin %Above / A

Step 4: Viability Check​

You need minimum 15-20% net margin after payment costs to cover:

  • Marketing (CAC)
  • Operating expenses
  • Profit

If net margin < 15%: Your business model is fragile. One chargeback spike kills profitability.

Worked Examples​

Example 1: $50 Product, 40% Margin, 0.5% CB Ratio (VIABLE)​

MetricAmount
Selling price$50.00
Product cost$30.00
Gross margin$20.00 (40%)
Processing (3.9%)-$1.95
Chargeback (0.5% × $85)-$0.43
Net after payments$17.62 (35.2%)
Marketing (CAC)-$10.00
Net profit$7.62 (15.2%)

Verdict: Viable. 15% net profit provides buffer.

Maximum sustainable CB ratio: 2.5% before unprofitable (but MATCH risk at 0.9%)

Example 2: $30 Product, 30% Margin, 1.5% CB Ratio (MARGINAL)​

MetricAmount
Selling price$30.00
Product cost$21.00
Gross margin$9.00 (30%)
Processing (4.3%)-$1.29
Chargeback (1.5% × $75)-$1.13
Net after payments$6.58 (21.9%)
Marketing (CAC)-$8.00
Net profit-$1.42 (LOSS)

Verdict: Not viable at 1.5% CB ratio. Must reduce to under 0.7% or increase prices.

Maximum sustainable CB ratio: 0.7% before unprofitable

Example 3: $100 SaaS Subscription, 80% Margin, 0.3% CB Ratio (HIGHLY VIABLE)​

MetricAmount
Selling price$100.00
Product cost$20.00 (hosting)
Gross margin$80.00 (80%)
Processing (3.2%)-$3.20
Chargeback (0.3% × $25)-$0.08
Net after payments$76.72 (76.7%)
Marketing (CAC amortized)-$5.00
Net profit$71.72 (71.7%)

Verdict: Highly viable. Massive margin buffer.

Maximum sustainable CB ratio: 10%+ (but MATCH risk at 0.9%)

Example 4: $20 Digital Product, 90% Margin, 2% CB Ratio (NOT VIABLE)​

MetricAmount
Selling price$20.00
Product cost$2.00
Gross margin$18.00 (90%)
Processing (4.9%)-$0.98
Chargeback (2% × $25)-$0.50
Fraud tool-$0.15 (required at 2% CB)
Net after payments$16.37 (81.9%)
Marketing (CAC)-$12.00
Net profit$4.37 (21.9%)

Verdict: Marginal. 2% CB ratio is above MATCH threshold (0.9%). You'll be terminated before you scale.

Maximum sustainable CB ratio: 0.8% (MATCH risk), but need under 0.5% for health

Chargeback Ratio Tolerance by Margin​

Gross MarginMax CB Ratio at 3.5% Payment CostsMax CB Ratio at 4.5% Payment Costs
20%0.3% (fragile)0.1% (very fragile)
30%0.8%0.5%
40%1.5%1.0%
50%2.5%2.0%
80%10%+10%+

BUT: MATCH threshold is 0.9% regardless of margin. You can't sustain >0.9% even if margin allows.

Practical max: Whatever is lower - margin-based OR 0.7% (safety buffer under MATCH)

Viability Decision Tree​

Industry-Specific Viability Checks​

Physical Goods E-Commerce​

Minimum requirements:

  • Gross margin: 35%+ (after COGS, before payments)
  • Expected CB ratio: Under 0.7%
  • AOV: $40+ (fixed fees hurt below this)

Red flags:

  • Margin under 25% (no buffer)
  • Commodity products (price competition kills margins)
  • Long shipping times (more disputes)

Verdict examples:

  • Luxury goods (60% margin): Highly viable
  • Apparel (40% margin): Viable if CB controlled
  • Low-cost accessories (25% margin): Fragile

Subscription SaaS​

Minimum requirements:

  • Gross margin: 60%+ (SaaS should have high margins)
  • LTV/CAC: 3:1 minimum
  • Churn: Under 5%/month

Red flags:

  • Margin under 50% (something's wrong with business model)
  • High involuntary churn (payment failures)

Verdict: Most SaaS is viable. Margins are high enough to absorb payment costs.

Digital Goods / Downloads​

Minimum requirements:

  • Gross margin: 70%+ (minimal COGS)
  • CB ratio: Under 0.8% (digital has higher fraud)
  • AOV: $25+ (fixed fees hurt below this)

Red flags:

  • High CB ratio (2%+) - fraud or quality issues
  • Low AOV (under $20) - fixed fees eat margin
  • No delivery proof - will lose disputes

Verdict examples:

  • Software downloads (90% margin): Highly viable
  • Courses/education (85% margin): Highly viable
  • Low-price PDFs (90% margin but $10 AOV): Marginal

Card-Present Retail​

Minimum requirements:

  • Gross margin: 30%+ (can be lower than CNP)
  • CB ratio: Under 0.3% (CP fraud is lower)
  • Foot traffic reliability

Red flags:

  • Margin under 25%
  • High-ticket items with long warranty periods

Verdict: Most retail is viable. Lower fraud and CB rates help thin margins.

When Payment Costs Kill Your Business Model​

Unviable scenarios:

1. Commodity E-Commerce (Thin Margins + Price Competition)​

Model:

  • Product: $25
  • Margin: 20% = $5
  • Payment cost: 4.5% = $1.13
  • Net: $3.87 (15.5%)
  • CAC: $8
  • Result: $4.13 loss per customer

Why it fails: Commodity pricing leaves no room for payment costs.

Fix: Impossible. Don't sell commodities on thin margins online.

2. High-CB Rate Business (Supplements, CBD-Adjacent)​

Model:

  • Product: $60
  • Margin: 50% = $30
  • Payment cost: 3.5% = $2.10
  • CB ratio: 2.5%
  • CB cost: 2.5% × $90 = $2.25
  • Net: $25.65 (42.8%)

Math works, but:

  • CB ratio 2.5% = MATCH listing within 3 months
  • No processor will keep you
  • Business model isn't sustainable

Fix: Reduce CB ratio to under 0.9% or find processors that accept high-risk.

3. Low-AOV Digital Goods (Fixed Fee Problem)​

Model:

  • Product: $10 digital download
  • Margin: 95% = $9.50
  • Payment cost: 5.9% = $0.59 (2.9% + $0.30)
  • Net: $8.91 (89%)

Math works, but:

  • CAC for $10 product: $5-8
  • Limited profitability
  • Volume needed is huge

Fix: Bundle products (3 for $25) to reduce fixed fee impact.

Viability Quick Test​

Answer these 5 questions:

  1. Gross margin after COGS: ____%

    • Under 20%: STOP (not viable for CNP)
    • 20-30%: Marginal (requires perfect execution)
    • 30-50%: Viable (if CB controlled)
    • Over 50%: Highly viable

  2. Expected chargeback ratio: ____%

    • Under 0.5%: Excellent
    • 0.5-0.7%: Manageable
    • 0.7-0.9%: At risk
    • Over 0.9%: Will be terminated

  3. Average order value: $______

    • Under $20: Fixed fees hurt
    • $20-50: Acceptable
    • Over $50: Fixed fees irrelevant

  4. Product cost if chargebacked: $______

    • Digital: Low cost (just fee)
    • Physical: Product + shipping lost
    • High cost = need very low CB ratio

  5. CAC (customer acquisition cost): $______

    • CAC > gross margin: Not viable
    • CAC = 50-70% of margin: Fragile
    • CAC < 30% of margin: Healthy

If you answered:

  • Questions 1-3 positively: Probably viable
  • Question 2 >0.9% or Question 4 is expensive: At risk
  • Question 5 CAC > margin: Not viable regardless of payments

Test to Run​

Pre-launch viability audit:

Week 1: Calculate unit economics

  1. Product price: $______
  2. COGS: $______
  3. Gross margin: $______ (___%)

Week 2: Add payment costs 4. Processing fee: $______ 5. Expected CB ratio: % 6. CB cost/transaction: $__ (ratio × true CB cost) 7. Net margin after payments: $______ (___%)

Week 3: Add acquisition costs 8. CAC estimate: $______ 9. Contribution margin: $______ (net margin - CAC) 10. If negative: Business not viable 11. If under 10%: Fragile, optimize before launch 12. If over 15%: Viable, proceed

Success criteria: Contribution margin over 15% after all costs including payments.

Scale Callouts​

Pre-launch:

  • Run this calculation BEFORE processing first payment
  • Model pessimistic scenario (1% CB ratio, not 0.3%)
  • Ensure 20%+ buffer

Under $100K/month:

  • Re-run calculation every quarter
  • Actual CB ratio may differ from projection
  • Adjust if contribution margin drops under 10%

$100K-$500K/month:

  • Model impact of hitting VAMP (0.9% CB ratio)
  • Calculate if business survives monitoring program fines
  • Need 25%+ margin to absorb payment spikes

Over $500K/month:

  • Quarterly model updates
  • Stress test: What if CB doubles?
  • What if processor raises rates?

When to Pivot or Quit​

Red flags your business model isn't viable:

1. Negative Contribution Margin​

If CAC + payment costs > gross margin:

  • You lose money on every sale
  • More sales = more losses
  • This is not fixable with scale

Action: Raise prices, reduce CAC, or quit

2. Can't Sustain Sub-0.9% CB Ratio​

If your business inherently has 1.5-3% CB ratio:

  • Supplements with aggressive marketing
  • High-ticket with long delivery (6+ weeks)
  • Digital goods without good evidence collection

Action: Either fix CB rate or accept you'll be terminated

3. Margin Compression Makes Payments Unaffordable​

If margin drops from 40% → 25% due to competition:

  • Payment costs stay fixed (3.5-4.5%)
  • Room for profit evaporates
  • Race to bottom

Action: Differentiate or exit market

4. Fixed Fee Problem on Low AOV​

If selling $15 products:

  • Processing: $0.74 (4.9% effective)
  • Almost 5% to payments alone
  • Margin must be 30%+ just to break even

Action: Increase AOV (bundles, upsells) or raise prices

Viability by Business Model​

High Viability​

Business TypeWhy Viable
SaaS (high ARPU)70-90% margins, low CB ratio, recurring revenue
Luxury goods50-70% margins, low fraud, high AOV
B2B services40-60% margins, very low CB ratio, high AOV
Digital products (courses)80-95% margins, provable delivery

Characteristics: High margin, low CB ratio, or both

Marginal Viability (Requires Perfect Execution)​

Business TypeWhy Marginal
Apparel35-45% margins, moderate CB (0.5-0.8%)
Consumer electronics20-35% margins, higher fraud risk
Subscription boxes35-50% margins, involuntary churn adds cost
Print-on-demand30-40% margins, shipping disputes common

Characteristics: Moderate margin with moderate CB risk

Requirement: Must keep CB under 0.6% and optimize processing costs

Low Viability (High Risk of Failure)​

Business TypeWhy Risky
Dropshipping15-25% margins, high CB (long shipping), high fraud
Supplements40-60% margins BUT 1.5-3% CB ratio (MATCH risk)
CBD productsGood margins BUT processors reject, MATCH risk
High-ticket furnitureDecent margins BUT long delivery = 2% CB ratio

Characteristics: Either thin margins OR unsustainably high CB ratio

Reality: These businesses struggle with payments regardless of demand

Alternative Payment Methods for Low Margins​

If your margin can't sustain 3-4% card processing:

AlternativeCostProsCons
ACH/bank transfer$0.20-1.00CheapSlow, returns, friction
Cash (card-present)$0FreeOnly works for local retail
SEPA (EU)0.8%Cheaper than cardsEU only, 8-week disputes
Invoice/NET 30$0No processing feesB2B only, collection risk

For sub-20% margin businesses: Explore alternatives to card payments.

Test to Run​

Margin stress test (simulate worst case):

Scenario 1: CB ratio doubles

  • Current CB ratio: ____%
  • Double it: ____%
  • Recalculate contribution margin: $______
  • Still profitable? Y/N

Scenario 2: Processor raises rates 0.5%

  • Current rate: ____%
  • New rate: ____%
  • Recalculate contribution margin: $______
  • Still viable? Y/N

Scenario 3: Enter monitoring program

  • Monthly fine: $25,000
  • Divide by monthly orders: $______ per order
  • Add to costs, recalculate margin: $______
  • Can you survive? Y/N

Success criteria: Your business remains profitable in all three scenarios. If not, you have no safety margin.

Where This Breaks​

  1. LTV assumptions for subscriptions: If you assume 12-month LTV but actual churn is 30%/month (3-month LTV), CAC destroys viability.

  2. CB ratio projections: First-time merchants assume 0.3% CB ratio. Reality is often 0.8-1.2% in first 6 months. Model pessimistically.

  3. Marketing cost creep: CAC doubles over time as channels saturate. Initial viability doesn't guarantee long-term viability.

  4. Returns not modeled: Returns are separate from chargebacks. If you have 10% returns + 0.5% chargebacks, your effective loss rate is 10.5%.

  5. Reserve lock-up not in P&L: $50K locked in reserves costs $4K/year in opportunity cost. Not in P&L but very real.

Next Steps​

Planning a new business?

  1. Calculate unit economics using this worksheet
  2. Model pessimistic payment costs (4.5% all-in)
  3. Ensure contribution margin >15%
  4. Review Total Cost Model for detailed budgeting

Existing business, margins compressing?

  1. Recalculate contribution margin with current costs
  2. If under 10%, you're at risk
  3. Optimize: Reduce chargebacks OR raise prices OR reduce CAC

Evaluating new market/product?

  1. Run viability model for new segment
  2. Compare to current business
  3. Don't launch if new segment has worse economics

See Also​