How to Measure eCommerce Success: Key Online Marketplace Metrics

When the Amazon founder, Jeff Bezos, was offered to sell advertising on the eCommerce marketplace store homepage, he answered that “It is one of the stupidest ideas I’ve ever heard.”

Nevertheless, he approved the idea, and currently, Amazon Advertising is worth almost $2.34 trillion (Stockanalysis) and is one of the most-profitable services’ virtual marketplace.

It demonstrates the Amazon Culture of Metrics in action. Bezos approved this idea solely because it was proved by data. If you plan to launch an eCommerce marketplace, understanding how data-driven decisions impact growth is crucial.

Metrics, or key performance indicators, help you to measure the success of an eCommerce business in achieving its goals.

There are multitudes of KPIs in eCommerce. To measure your eCommerce multi-seller marketplace platform success accurately, it’s best to form a set of metrics on the basis of your goals.

What Are Online Marketplace Metrics, and Why Are They Important?

Online marketplace metrics are quantifiable measures used to evaluate the performance and health of an online marketplace. These eCommerce success metrics provide valuable insights into various aspects of the marketplace, such as user engagement, revenue growth, customer acquisition cost, and retention. By understanding and analyzing these metrics, marketplace operators can identify areas for improvement, and optimize the overall performance of their platform.

For instance, tracking customer acquisition metrics can help you understand how effectively your marketing strategies are attracting new users. Similarly, monitoring revenue growth metrics can provide insights into the financial health of your marketplace. In essence, marketplace metrics are crucial for ensuring that your marketplace is on the right track to achieving its business goals. This includes calculating LTV in eCommerce to evaluate long-term profitability.

How to Identify Key Performance Indicators (KPIs) for Your Marketplace

Identifying the right marketplace KPIs is essential for tracking progress and achieving your business goals. Here are the steps to follow.

1. Define your business requirements. Start by determining what you want to achieve with your marketplace. This could include goals such as increasing revenue, improving customer satisfaction, or expanding your user base.
2. Identify relevant metrics. Choose metrics that align with your business goals and provide insights into the performance of your marketplace. For example, if your goal is to increase revenue, relevant metrics might include GMV and average order value.
3. Set targets and benchmarks. Establish targets and benchmarks for each metric to measure progress and identify areas for improvement. This helps you stay focused on your goals and track your performance over time.
4. Track and analyze data. Collect and analyze data on each metric to gain insights into the performance of your marketplace. Use tools like Google Analytics to monitor your metrics and identify trends.
5. Adjust and refine. Based on the insights gained from tracking and analyzing data, refine your KPIs and targets. This ensures that your KPIs remain relevant and aligned with your evolving business goals.

Types of Marketplace Metrics

There are several types of marketplace metrics that you should be aware of.

• Size metrics. These metrics measure the scale and value-add of the marketplace. Examples include Gross Merchandise Value (GMV), Average Order Value (AOV), total sales, and revenue metrics. GMV, for instance, reflects the total value of goods sold through the marketplace, providing a clear picture of its overall size and growth.
• Shape metrics. These metrics measure the fragmentation or concentration of the marketplace. Key metrics for marketplaces in this category include buyer to seller ratio, the number of active buyers and sellers. These metrics help you understand the distribution of activity across your marketplace.
• Liquidity metrics. These metrics measure the efficiency of the marketplace in matching buyers and sellers. Important liquidity metrics include the number of transactions, fulfillment rates, and match rate. High liquidity indicates a well-functioning marketplace where buyers and sellers can easily find each other.
• Acquisition metrics. These metrics measure the effectiveness of user acquisition strategies. This category includes Customer Acquisition Cost (CAC), seller acquisition cost, and conversion rates. Monitoring these metrics helps you evaluate the cost-effectiveness of your marketing efforts and optimize your customer acquisition strategies.
• Retention and engagement metrics. These metrics measure the loyalty and engagement of users. Examples include user engagement rates, repeat purchase rates, and daily/monthly active users. High retention and engagement rates indicate satisfied and loyal customers who are likely to make repeat purchases.
• Unit economics metrics. These metrics measure the financial health of the marketplace. KPIsinclude contribution margin, Return on Investment (ROI), Lifetime Value (LTV) and the LTV/CAC ratio. These metrics help you understand the long-term profitability of your customer base and ensure that your customer acquisition efforts are sustainable.

Size Metrics: Your Business Growth and Profitability

These are fundamental KPIs to evaluate business development in eCommerce for online shopping marketplaces. They provide insights into the overall performance and growth potential by measuring key financial indicators. 

Gross Merchandise Volume (GMV)

GMV is an equivalent of the total order value, and is measuring the dollar value of items sold in an Internet marketplace mall over a given period of time.

It is an essential KPI for eCommerce multi-seller marketplaces that helps to measure business growth, and the usage of a virtual shopping mall website by sellers. Moreover, understanding the sales funnel helps you measure the effectiveness of guiding customers from initial interest to completing a purchase, thereby improving conversion rates.

GMV is calculated prior to the deduction of any expenses, although shipping fees, net of refunds and returns, should be excluded.

It is most useful as a comparative measure over time and is tracked on a monthly and yearly basis.

For service online shopping marketplaces, it’s important to take into account the difference between “contracted” and “delivered” GMV figures. In some service Internet shopping mall concepts, such as house selling platform Opendoor, there can be a delay between the two, which can cause incorrect GMV, if “contracted” figures are computed.

Gross merchandise sales (GMS)

Apart from GMV, there is a similar KPI used to measure the total value of goods sold on a platform–GMS or Gross Merchandise Sales. While these terms are often used interchangeably, they can have slight differences depending on the company.

GMV vs GMS

• GMV: Represents the total value of all merchandise sold through a platform within a specific period, including shipping fees and before deductions for refunds or cancellations.
• GMS: Specifically used by Etsy, it represents the dollar value of items sold in all Etsy marketplaces, excluding shipping fees and net of refunds associated with canceled transactions.

Different companies may use different metrics to measure similar concepts: eBay uses GMV, while Etsy uses GMS.

Etsy GMS, the online marketplace equivalent of GMV

eBay Gross Merchandise Volume* growth year over year

Neither GMV nor GMS directly translate to company revenue. For example, in Q2 2024, eBay’s GMV was $18.4 billion, but its actual revenue was $2.57 billion.

Revenue

Revenue is a key metric that measures the income that the eCommerce multi-seller marketplace receives in the form of transaction fees, listing fees, and seller services.

It helps to track the efficiency of the virtual shopping mall website concept, and break down the revenue flow to analyze its components.

Etsy’s annual revenue

The online shopping marketplace revenue comprises two parts.

1. an eCommerce marketplace store transaction fee and listing fee;
2. seller services: direct checkout, promoted listings, shipping labels.

The metric helps the eCommerce multi-seller marketplace platform track the efficiency of both parts of the revenue.

For the second part of the revenue—seller services, the virtual marketplace store has detailed metrics as well.

Etsy revenue breakdown

It helps to track and increase the efficiency of the Internet marketplace monetization model concept.

To gain a more granular view of seller services (value-added services), use an Average revenue per user metric.

Revenue also helps you  track the overall eCommerce multi-seller marketplace growth year over year.

It is calculated differently for various eCommerce marketplace stores, here is a guide on how to count it correctly.

Net Revenue

Net revenue is the total revenue generated after deducting returns, discounts, and other expenses. For instance, if your marketplace has a gross revenue of $1 million but incurs $200,000 in returns and discounts, your net revenue would be $800,000. Monitoring net revenue provides a clear picture of your marketplace’s financial performance, with successful platforms aiming for consistent growth.

Average Revenue Generated

This metric is calculated by dividing the total revenue by the number of transactions or customers over a defined time frame. It provides insights into profitability per transaction.

Calculating the average revenue generated per transaction is crucial for understanding pricing strategies. For example, if your marketplace has a total sales value of $500,000 from 10,000 transactions, the average revenue would be $50 per transaction. Aiming for a consistent or growing average revenue is essential; many successful marketplaces target an increase of 5-10% annually.

Total Sales 

These metrics are vital for assessing marketplace health and revenue potential.

• Total Sales Value refers to the monetary amount generated from all sales within a specific period. For instance, if your marketplace generates $1 million in sales over a quarter, this figure serves as a benchmark for evaluating growth. Many successful marketplaces aim for a 20-30% increase in total sales value year-over-year.
• Total Sales Volume measures the total quantity of goods sold. A marketplace like Amazon typically sees millions of transactions daily. For smaller marketplaces, a benchmark could be around 1,000 transactions per month for a healthy growth trajectory. Monitoring sales volume helps to identify trends and manage inventory effectively.

Average Order Value (AOV)

It reflects how much customers spend for every order they make, sales per each order, not per customer.

This metric helps to see your virtual marketplace store growth by reflecting the average transaction value, and profit increase.

Additionally, it gives insights about customers’ behavior.

• whether or not clients are buying multiple items;
• the items of what cost is the most popular on an eCommerce multi-seller marketplace platform;
• the volume and frequency at which buyers are willing to spend.

It’s calculated monthly, weekly or daily, by dividing the total revenue by the number of transactions.

AOV = total revenue / number of transactions

By increasing AOV, you automatically increase Return on Marketing Investment (ROMI).

Shape Metrics: Activity Distribution

These metrics do not reflect the performance that is directly connected with the eCommerce marketplace store’s main goals, like conversion and purchasing, and are useful when you are actively embracing the new market category, or scaling your virtual shopping mall website concept. The KPIs help stakeholders understand the distribution of activity among participants, such as buyers and sellers.

Supply-Side Development: Quantitative Growth

Quantitative growth on the supply side of a marketplace refers to the increase in the number of suppliers or vendors who list their products or services on the platform. This growth is crucial for expanding the variety of offerings available to buyers and enhancing the overall value proposition of the marketplace. To measure quantitative growth, consider tracking the following metrics.

• Number of active suppliers. This metric tracks the number of suppliers who have listed products or services on the marketplace. Monitoring the number of active suppliers helps you understand the scale of your supply side and identify trends in supplier engagement. It’s best to measure active sellers’ growth, with the monthly active users‘ metric), like Etsy.

Source: Backlinko

• Suppliers’ growth rate;
• Number of listings, and for a services web marketplace, count the number of active Suppliers at a specific time instead;
• Listings growth rate;
• Users’ churn.
• Supplier acquisition rate. This metric measures the rate at which new suppliers are acquired, typically expressed as the number of new suppliers added per month or quarter. A high supplier acquisition rate indicates effective supplier recruitment strategies and a growing supply base.
• Supplier retention rate. This metric tracks the percentage of suppliers who remain active on the marketplace over a given period. It is calculated by dividing the number of suppliers who continue to list products or services by the total number of suppliers at the start of the period. A high retention rate suggests that suppliers find value in your marketplace and are likely to continue using it.

By tracking these metrics, marketplace operators can gain valuable insights into the growth and development of the supply side of their platform. This information can be used to optimize supplier acquisition and retention strategies, ensuring a robust and diverse supply base that meets the needs of buyers.

Supply-Side Development: Qualitative Growth

These KPIs help to see not only your Internet marketplace mall performance growth but give insights on what is influencing that growth. They are also applicable for the demand side.

• Users Concentration: number of sellers vs. the percentage of business they generate over a period of time; it is measured with whale curves metric.

It helps to track the most successful seller’s percentage and to define which seller types, goods or services are your virtual marketplace store growth drivers.

• Cohort Analysis: showcases the continued activity of a group of users acquired during a specific period of time, a week, month or a year ago.

Without metrics that are based on cohorts, you can only track which channel is driving the most traffic.

Etsy visits by channel

With such metrics, by analyzing the behavior of cohorts —user groups who came through those channels a month or a year ago, you can also tell which channels are driving the most conversions.

Demand-Side Development: Quantitative growth

Source: Backlinko

• Overall number of customers, and active buyers amount;
• Buyer growth rate;
• Churn rate.

Demand-Side Development: Qualitative Growth

• Average dollar amount purchased per buyer;
• Average number of orders per buyer;
• Average order growth per buyer;
• Customers’ satisfaction, measured regularly through the NPS (Net Promoter Score) metric and customer feedback;
• Customer conversion percentage;
• Repeat purchases.

Etsy’s repeat purchases metrics

Buyer to Seller Ratio

The buyer to seller ratio indicates the balance between buyers and sellers on your platform. A typical benchmark for a healthy marketplace is a ratio of 3.1 (three buyers for every seller).

It is calculated using the formula.

Buyer to Seller Ratio=Total Buyers/Total Sellers

This ratio varies by marketplace type; for instance, in B2B settings, it can range from 1.1 to 1.6 depending on supply and demand dynamics. If your marketplace has 300 sellers, aim for at least 900 buyers. A balanced ratio ensures that sellers have enough potential customers, which can lead to increased sales and seller satisfaction.

Read more: B2B eCommerce marketplace: Platforms, Building Guide, and Success Principles

Liquidity Metrics: Transaction Efficiency

The marketplace liquidity indicates how successful the eCommerce multi-seller marketplace platform is for sellers and buyers, and shows a marketplace ability to scale and maintain strong marketplace performance.

Liquidity 

It’s calculated through the following formula.

Customer liquidity = visits on a given time period / transaction number

The KPI may be counted differently depending on an eCommerce marketplace store type.

On Etsy, it is the proportion of total stock which is sold monthly. On Airbnb, it is the proportion of rooms which are booked each night. On Uber, it’s the percentage of drivers that are driving customers at any given hour.

Thus, there are basic metrics that help to track liquidity on any online shopping marketplace.

• how long it takes to make a transaction;
• the percentage of goods or services that are purchased hourly, daily, monthly;
• the percentage of listings that lead to transactions within a certain time period.

Match rate

The match rate measures the efficiency of a marketplace in successfully connecting buyers with sellers. It indicates the percentage of buyer requests that result in successful transactions.

Match Rate=Number of Successful Transactions/Total Buyer Requests×100

This metric assesses how well the marketplace facilitates transactions between buyers and sellers. A high match rate indicates that the marketplace is effectively meeting buyer needs and facilitating sales.

The match metric is important for evaluating the performance of the marketplace, user satisfaction, and operational efficiency.

Fulfillment rates

It reflects the percentage of the times when your online shopping marketplace delivers goods or services as promised.

It’s calculated through the following formula.

Fulfillment rate = The number of fulfilled orders / Total number of orders (including rejected, but excluding canceled orders)

If fulfillment rates are getting negative, it’s necessary to use more narrow metrics to identify the reasons: if there are particular items, services or suppliers with the most frequent fulfillment failures.

These are two liquidity-crucial B2B marketplace KPIs, ensuring that transactions are completed as intended.

The Contract compliance rate measures the percentage of contracts that adhere to the agreed-upon terms and conditions. It is crucial for maintaining supplier relationships and minimizing risks. For example, organizations might aim for a target of 95% compliance within a specific timeframe after contract implementation.

The Contract Completion Rate indicates the percentage of contracts that have been fully executed and fulfilled according to their terms. It can be calculated as:

Contract Completion Rate=(Number of Completed Contracts/Total Number of Contracts)×100

High completion rates are indicative of effective contract management practices and adherence to deadlines.

Acquisition Metrics: Growth Strategies

Acquisition metrics evaluate the effectiveness of strategies aimed at attracting new users to the marketplace. 

Read more: How to Scale Marketplace: Focus Points and Metrics

Customer Acquisition Cost (CAC)

This metric shows how much you need to spend to get a paying customer.

It reflects not only soft results such as clicks or page views, but your revenue, since it measures your performance in making somebody a customer.

You may invest marketing budgets to get good pageview results but will gain one sale out of those results. It means, your cost per acquisition is the entire budget spent to date.

That’s why it’s necessary to use the CAC metric when measuring your marketing efforts.

It’s calculated by the following formula: Cost Per Acquisition = Total costs associated with acquisition / Total new customers over the measured time period

Seller Acquisition Cost

Understanding seller acquisition cost is vital for budgeting. If it costs your marketplace $200 to acquire a new seller, you need to ensure that their contribution to revenue justifies this cost. A benchmark for a sustainable marketplace is to keep seller acquisition costs below 20% of the average revenue generated from each seller.

Conversion Rate

The conversion rate (CVR) is a vital metric in digital marketing and eCommerce, representing the percentage of users who complete a desired action—such as making a purchase, signing up for a newsletter, or clicking a specific call-to-action (CTA)—out of the total number of visitors. To calculate the conversion rate, use the formula.

Conversion Rate = (Conversions / Total Visitors) × 100

For instance, if an eCommerce site receives 1,000 visitors in a month and generates 50 sales, the conversion rate would be 5%.

The effectiveness of the sales funnel can significantly impact conversion rates, as it guides customers from initial interest to completing a purchase.

A higher conversion rate indicates that a website or marketing campaign effectively turns visitors into customers, making it essential for assessing marketing performance, optimizing website design, and enhancing user experience. Average conversion rates vary by industry. eCommerce typically sees rates between 2% and 5%, while B2B services often range from 1% to 3% due to longer decision-making processes. Lead generation can achieve conversion rates of 5% to 10%, depending on the effectiveness of lead nurturing.

Several factors influence conversion rates, including website design and usability, understanding the target audience, effective marketing strategies, and competitive pricing or promotions. Monitoring and optimizing these rates is crucial for businesses aiming to maximize their return on investment (ROI) from digital marketing efforts, ultimately enhancing overall performance and profitability.

Network Growth Rate

This is a specific B2B marketplace metric that assesses the rate at which a B2B marketplace expands its network of buyers and sellers over a specific period. It can be calculated by comparing the number of active users (buyers or sellers) at two different points in time:

Network Growth Rate=(Active Users at End Period−Active Users at Start Period/Active Users at Start Period)×100

A positive growth rate indicates successful acquisition strategies and marketplace expansion efforts, which are vital for increasing transaction volume and enhancing marketplace vitality. This metric is especially useful for tracking B2B marketplace growth, where both buyer and supplier expansion drive long-term scalability.

Retention and Engagement Metrics: User Loyalty

Retention and engagement metrics are crucial for measuring user loyalty and the ongoing engagement of participants within the marketplace. 

User Engagement

User engagement can be quantified through metrics such as.

• Daily Active Users (DAU). The number of unique users engaging with the platform daily. A healthy benchmark for smaller marketplaces is around 100-500 DAU, while larger platforms like eBay might see millions. Tracking DAU helps to assess user interest and engagement levels.
• Repeat Buyer Ratio. This measures the percentage of buyers who make multiple purchases, indicating customer loyalty and satisfaction.

High user engagement reflects active interaction with your platform. Metrics such as time spent on site, pages viewed, and interaction rates are vital. For instance, an average session duration of 3-5 minutes and 5-7 pages viewed per visit are good benchmarks. Engaged users are more likely to convert into buyers, making this metric crucial for growth.

Analyzing the sales funnel can provide insights into how effectively your platform is engaging users and converting them into buyers.

Client’s acquisition and retention

There are a multitude of metrics aimed to measure communication with clients. While some of them are soft KPIs that help you to track intermediate results like cost per click, the following are fundamental metrics, which show if you get a real value, purchases, and repeat buyers, in return for your investments.

User retention measures the percentage of users who continue to engage with the marketplace over time. A benchmark for good user retention is around 40-60% after the first month. For example, if you have 1,000 new users, aim to retain at least 400-600 of them after one month. High retention rates indicate customer satisfaction and loyalty.

Customer Retention is similar to user retention, but focuses on repeat buyers.

Customer Retention Rate=(Customers at Start of Period/Customers at End of Period−New Customers​)×100

High retention rates suggest effective engagement strategies and customer satisfaction.

Successful marketplaces often see retention rates of 30-50%. For instance, if you have 1,000 customers, aim to have 300-500 return for additional purchases within a year. Implementing loyalty programs can help boost this metric.

Read more: How Custom Commission Structures Can Help Retain Vendors and Maintain a Profitable Marketplace

GMV Retention

Retention is a cohort-based metric that measures the percentage of Gross Merchandise Value retained from customers over time, offering insights into the health and sustainability of a marketplace or e-commerce platform by evaluating customer spending retention. GMV retention is calculated by dividing the GMV generated by returning customers in a given period by the total GMV from the initial period for that cohort. High GMV retention signifies a stable and loyal customer base, essential for long-term growth and profitability. Unlike user retention, which measures how many customers return, GMV retention focuses on the value of their transactions. For instance, if 10 users spend $10,000 in January and 5 return in February spending $7,500, the user retention is 50%, but GMV retention is 75%. In marketplaces, supply-side GMV retention is often higher than demand-side, with best-in-class marketplaces potentially exceeding 100% retention through month 12, while average marketplaces retain around 80-95% in the first three months, plateauing at 45-50% by month 12. Factors such as product quality, customer satisfaction, pricing strategies, and effective marketing influence GMV retention, which can lead to more accurate revenue forecasting, identification of growth opportunities, increased profitability, and a competitive edge in the market.

Unit Economics Metrics: Profitability Analysis

Unit economics metrics focus on the financial health of the marketplace by analyzing the profitability of individual transactions and customer relationships.

Return on Investment (ROI)

The metric shows what you gain out of your marketing investment—whether it’s profitable or not.

It’s calculated through the following formula.

ROI = (Profit – Investment) / Investment x 100

When using the metric, it’s necessary to take into account not only the instant profit but long-term benefits as well.

Your investments are: $5000 in organic traffic, and $500 in a paid ad.

Number of clients acquired: 30 through organic traffic and 10 through a paid ad.

Average checkout amount for both: $150

Therefore, ROI out of organic traffic:

(30 Х 150) — 5000) / 5000 Х 100 = — 10%

ROI out of a paid ad:

(10 Х 150) — 500) / 500 Х 100 = 200%

The metric shows that a paid ad results in a better profit.

However, ROI should always be calculated considering another metric—Customer Lifetime Value.

Customer Lifetime Value is the total amount of sales that a client has generated over time.

The way Customer Lifetime Value is affecting ROI results is the difference in the quality of traffic that organic traffic and a paid ad brings.

Online customers that came through organic traffic are of much better quality and are more loyal, therefore, the probability is high in such a way that they are the ones who make repeat purchases.

Thus, the Customer Lifetime Value metric can bring the following data to the equation.

Average Customer Lifetime Value for clients from organic traffic: $10,000.

Average Customer Lifetime Value for clients from paid ads: $600.

In this case, you take into account the long-term profit as well, and ROI is the following.

ROI out of organic traffic:

(10000 — 5000) / 5000 Х 100 = 100%

ROI out of a paid ad:

(1500 — 500) / 500 Х 100 = 200%

Calculating ROI in this way will lead to a clearer picture in terms of the long-term profit that you get.

Contribution Margin

The contribution margin represents profitability after accounting for variable costs. A healthy contribution margin typically ranges from 30-50%. For example, if your marketplace generates $500,000 in sales with $250,000 in variable costs, your contribution margin would be 50%. This margin is a key metric crucial for covering fixed costs and achieving profitability.

Final Thoughts

Those are fundamental metrics that help in measuring the main points of your Internet marketplace mall performance accurately.

However, a good deal of eCommerce multi-seller marketplaces have different sets of KPIs. They were formed on the basis of online mall goals or concepts.

Etsy set of KPIs

• Gross Merchandise Value;
• percent mobile Gross Merchandise Value;
• active sellers / active buyers;
• percent mobile visits;
• percent international GMV;
• the top retail categories.

The virtual shopping mall website is measuring the percentage of Gross Merchandise Value gained through mobile, since its intended audience is actively purchasing through mobile devices. In the Etsy example, 60% of the virtual marketplace store GMV came from mobile purchases.

Read more: Mobile Commerce Explained: Enhancing Customer Experience and Convenience

Case Study — Identifying the Right KPIs From the Start

TackleTarts, a custom fishing marketplace founded in 2019, successfully identified key metrics to drive its growth and development. Initially launching a minimal viable product within nine months, the founders tracked revenue growth from £0 to £100 per month to validate their concept and attract investment. Customizing the CS-Cart platform was essential, focusing on metrics like vendor panel usability and payment system efficiency to enhance user experience. As the marketplace expanded, they prioritized metrics such as customer acquisition cost and average order value, addressing challenges while building trust with vendors and customers. Within 2–3 years, TackleTarts achieved thousands of products and hundreds of vendors, positioning itself for continued success and growth in the fishing industry.

Read more: Case Study: TackleTarts—a Custom Fishing Marketplace on CS-Cart Built in 1 Year

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