Building a marketplace requires understanding foundational terminology that shapes business decisions. New founders often make critical errors by conflating metrics like GMV with actual revenue, which can derail forecasting, capital raising, and company sustainability.
The core distinction: GMV is the value of transactions happening on your platform. Revenue is the money your company actually keeps.
GMV (Gross Merchandise Value)
Gross GMV represents the total transaction value flowing through a marketplace. It serves as a leading indicator of marketplace health by revealing demand creation, supply onboarding, and liquidity unlocking.
This metric reveals:
- Supply strength (availability, pricing, quality)
- Demand strength (traffic, conversion, purchase intent)
- Liquidity effectiveness
- Seasonality patterns
- Performance by geography, category, or cohort
Consistent GMV growth indicates a functioning marketplace ecosystem.
Completed GMV / Net GMV
This metric excludes cancellations, no-shows, refunds, failed payments, chargebacks, and fraud. The gap between Gross and Completed GMV diagnoses operational issues including funnel leaks, trust gaps, inefficiencies, supply quality problems, pricing mismatches, UX friction, and settlement complications.
Watch this spread closely. A widening gap between gross and completed GMV is often the first signal of a trust or quality problem.
Revenue
Revenue represents the portion of GMV a company retains, meaning the actual money available for operations, staffing, marketing, and product development. It depends on two factors: take rate and transaction quality.
Take Rate
Take rate is the percentage of each transaction the marketplace retains. It is a fundamental lever affecting revenue generation and operational sustainability.
Strong take rates reflect platform value delivery rather than simple price increases. Factors influencing take rate include:
- Supply quality and scarcity
- Trust and marketplace-created friction reduction
- Protective offerings (insurance, guarantees, verification)
- UX improvements reducing discovery friction
- Competitive positioning
- Ecosystem depth and repeat-use behavior
Even modest take rate improvements significantly impact contribution margin and revenue.
Take Rate vs. Revenue: Take rate is a percentage; revenue is actual dollars earned. $1,000,000 in completed GMV at a 10% take rate produces $100,000 revenue. Increasing to 12% yields $120,000 without acquiring new customers.
AOV (Average Order Value)
AOV measures per-transaction buyer spending, influencing unit economics and marketing efficiency. It helps determine if buyers select higher-value supply and whether margins improve as platforms scale.
TAM (Total Addressable Market)
TAM represents the total possible GMV if a marketplace captured 100% market share, defining business scale ceiling and long-term potential. For marketplaces, TAM should be expressed in GMV terms, not revenue. See the TAM article for the full methodology.
Liquidity
Liquidity measures how effectively supply and demand connect and complete transactions. Strong liquidity correlates with faster user matching, higher CAC efficiency, improved conversion, and stronger retention.
Overall Liquidity provides aggregate ecosystem functionality signals.
Market-Level Liquidity examines specific geographies, categories, or verticals where performance varies.
Common measurement methods:
- Match Rate: Percentage of buyer requests successfully matching supply
- Fill Rate: Percentage of supply inventory booked or sold
- Time to Match: Duration to find counterparts
- Search-to-Book Conversion: Transaction completion rate after searching
- Inquiry-to-Book Rate: Service inquiry-to-payment conversion
CAC (Customer Acquisition Cost)
CAC represents total acquisition expense divided by new users gained. Marketplaces must track CAC separately for buyers and sellers due to different acquisition channels, conversion patterns, and payback expectations.
Retention Rate
Retention measures user return frequency and engagement over time. Buyer retention signals trust, supply reliability, and smooth experiences. Seller retention indicates healthy utilization, adequate earnings, and consistent demand.
LTV (Lifetime Value)
LTV calculates total value generated by a user before churn.
Buyer LTV: Average Order Value × Purchase Frequency × Buyer Take Rate × Expected Lifespan
Example: $100 AOV × 2 annual purchases × 15% take rate × 3 years = $90 buyer LTV
Seller LTV: (Annual GMV × Seller Take Rate) × Expected Lifespan
Example: $50,000 annual GMV × 20% take rate × 4 years = $40,000 seller LTV
Separate side calculations reveal where economics strengthen or weaken and determine sustainable acquisition spending.
Contribution Margin
Contribution margin represents profit remaining after deducting transaction-specific variable costs including payment processing, refunds, chargebacks, customer service, trust and safety, partner payouts, and insurance.
This metric indicates:
- Per-transaction profitability
- True marketplace scalability
- Paid marketing affordability
- Growth sustainability without additional capital
Strong contribution margins compound over time, improving operational leverage.
Supply-Side vs. Demand-Side
These user groups (also called sell-side and buy-side) have different needs, incentives, economics, and churn patterns. Supply focuses on earnings, utilization, and demand quality; demand prioritizes availability, pricing, trust, and usability. Treating these groups identically breaks operational strategy.
Utilization
Utilization measures how frequently supply generates value. For service, rental, and asset-based models, utilization directly impacts seller earnings. High utilization indicates busy providers; low utilization signals idle capacity, seller frustration, and weakened liquidity.
Churn
Churn measures user departure rates. Seller churn often indicates low utilization or poor earnings; buyer churn typically signals weak supply, pricing issues, or experience friction. Track each side separately.
Trust and Safety
Trust and Safety encompasses identity verification, fraud prevention, dispute resolution, payments compliance, content moderation, and policy enforcement.
Common marketplace fraud risks include:
- Friendly fraud (legitimate charge disputes)
- Credit card fraud (stolen payment methods)
- Account takeover
- Supplier misrepresentation
- Synthetic identities
- Double bookings
- Collusion
- Off-platform transactions
- Chargebacks
- Refund abuse
Balanced Trust and Safety programs protect users while maintaining experience quality, ensuring compliance with financial and legal requirements, and building the foundation for sustainable liquidity.
These metrics are not isolated numbers. They are an interconnected system. Understanding them together (how take rate affects revenue, how liquidity affects CAC, how churn affects LTV) is what separates founders who scale from founders who plateau.