One of the most frequent complaints we hear from eCommerce and marketing directors when they evaluate their relationship with their current agency is this: “They send us a report full of numbers, but we don’t know if we’re doing well or badly.”
And it’s a real problem. eCommerce generates an overwhelming amount of data: impressions, clicks, sessions, conversions, orders, returns, ratings, ranking positions, advertising costs, gross revenue, net revenue. Having access to all that data doesn’t mean having visibility into the business. It can mean exactly the opposite: paralysis from information overload.
An excellent eCommerce agency doesn’t report everything it can measure. It reports what matters for the client’s business, what enables decisions, and what allows an objective evaluation of whether the work is generating value.
In this article we define the 7 KPIs we consider essential in any eCommerce agency report, how to calculate them correctly, how to interpret them, and how to present them to a leadership team or C-suite.
Why most agency reports fail
Before getting into the KPIs, it’s important to understand why reporting is such a frequent problem in the industry.
Vanity metrics bias: Agencies report metrics that make the work look good, not necessarily the ones most relevant to the client’s business. Impressions went up, followers increased, campaign reach was huge. These numbers look good in a presentation, but they don’t tell you whether sales grew or margin improved.
Lack of context: A number without context is noise. Saying ROAS was 4.2x this month says nothing if it isn’t compared to last month’s ROAS, to the defined target, to the category benchmark. Context is what turns a data point into an insight.
Lack of causality: The report says sales went up 15% this month. Why? Was it the Meta campaign? Was it listing optimization? Was it seasonality? Was it the discount you ran? Without causality, the report doesn’t let you learn or replicate successes.
Metrics that aren’t in the same unit as the business: Executives think in pesos, dollars and margins. If the report talks about CPM, CTR and Quality Score without translating them into revenue and profitability impact, the report has no natural audience among company leadership.
The 7 essential eCommerce KPIs
KPI #1: GMV (Gross Merchandise Value) by channel
What it measures: The total value of sales processed on each eCommerce channel (MercadoLibre, Amazon, D2C store, etc.), before discounts, returns and fees.
Why it’s first: GMV is the operation’s scale indicator. It’s the number that speaks the same language as the finance department: how much was sold. It’s the starting point of every business discussion.
How to report it correctly:
- Broken down by channel (not just the consolidated total).
- Compared vs. the same period last year (year-over-year) and vs. the previous month (month-over-month).
- With the period’s target, so progress vs. plan can be evaluated.
- With the last 3-6 months’ trend, to identify whether growth is sustained or one-off.
Warning sign: Total GMV growth that’s concentrated in a single channel while others stagnate. Can indicate excessive dependency and business risk.
How to interpret it for the C-suite: “We closed the month with $X million in online sales, a Y% increase vs. the same month last year. The MercadoLibre channel grew Z%, while the D2C channel accelerated its growth to W%.”
KPI #2: Net Revenue by Channel (Contribution Margin)
What it measures: The revenue left after subtracting the marketplace fee, the advertising cost on that platform, and the logistics cost. Also called Contribution Margin by channel.
Why it’s critical: Gross GMV can be misleading. An operation can have high GMV with margins so tight they leave practically no money for the company. Net Revenue by Channel shows each channel’s financial reality.
How to calculate it:
Net Revenue = GMV
- Marketplace fee (10-18%)
- Channel advertising spend (Mercado Ads, Amazon Ads)
- Logistics cost (MercadoFull, FBA, or own 3PL)
- Returns and cancellationsHow to report it: As a comparative table by channel, showing: GMV, fee %, advertising %, logistics %, Net Revenue, and Net Revenue as % of GMV.
Warning sign: A channel with high GMV but Net Revenue below 60% of gross GMV can indicate inefficiency in advertising or logistics. A channel mix where the highest-margin channel (usually D2C) isn’t growing while the lowest-margin ones (highly competitive marketplaces) are, is a sign of structural profitability erosion.
KPI #3: Conversion Rate by Traffic Source
What it measures: The percentage of visitors who complete a purchase, segmented by the source that traffic comes from (marketplace organic, marketplace paid, Meta Ads, Google Ads, email, direct).
Why it matters: Conversion rate is the most direct indicator of shopping experience quality. If traffic arrives but doesn’t convert, the problem isn’t acquisition: it’s product, price, content, UX or trust.
Reference benchmarks by channel:
- Organic marketplace (MercadoLibre, Amazon): 3-8% is a healthy range for mass consumption categories.
- D2C store from email marketing: 4-12% (the audience is more qualified).
- D2C store from Meta Ads: 1-3% (colder audience).
- D2C store from Google Shopping: 2-5%.
How to report it: A bar chart by traffic source, with the current period’s conversion rate vs. the previous period. Highlight traffic sources that are improving and those that are deteriorating.
Warning sign: A drop in marketplace conversion rate can indicate problems with listing content, deteriorating seller reputation, or competitors appearing with a better offer. A drop in D2C can indicate UX problems, prices misaligned with the market, or deteriorating paid traffic quality.
KPI #4: ROAS (Return on Ad Spend) by Platform
What it measures: For every peso or dollar invested in digital advertising, how much revenue was generated. Calculated as Attributed Revenue / Ad Spend.
Why it’s the king metric of media efficiency: ROAS lets you compare the efficiency of different advertising channels and make budget allocation decisions based on data. Without this number, media budget is allocated by gut feeling or inertia.
Minimum healthy ROAS by channel: The minimum acceptable ROAS varies by category and by the product’s gross margin. The general rule is that the minimum ROAS for a campaign not to be margin-destructive is:
Minimum ROAS = 1 / Product gross marginIf your gross margin is 40%, your minimum ROAS is 2.5x. If your margin is 60%, it’s 1.7x. Below that number, advertising is destroying margin.
Target ROAS by channel (reference for LATAM 2025):
- Mercado Ads (Sponsored Products): 4-8x target in competitive categories.
- Amazon Ads: 3-7x target.
- Meta Ads (traffic to D2C): 2.5-5x target depending on category.
- Google Shopping: 3-6x target.
How to report it: A table with spend, attributed revenue and ROAS by advertising platform, compared vs. target and vs. the previous period. Include ROAS evolution over time to detect efficiency trends.
Warning sign: ROAS below the minimum calculated for your margin is real money loss, even if absolute revenue is growing. Stable ROAS but flat sales volume can indicate you’ve already hit the efficiency ceiling of your current audience and need to expand.
KPI #5: Share of Search on Marketplaces
What it measures: The percentage of relevant search results where your brand appears in the top organic positions, for your category’s most important keywords.
Why it’s a strategic KPI: Share of search is the long-term marketplace positioning indicator. This month’s revenue can vary due to seasonal or promotional factors. Share of search tells you whether your brand is gaining or losing structural ground on the platform.
How to measure it: Tools like Nubimetrics (for MercadoLibre) let you monitor organic positions for specific keywords. For Amazon, Jungle Scout and Helium 10 offer similar functionality. The methodology: define a set of 10-30 critical keywords for your category, monitor your average position on those keywords weekly, and calculate what percentage of those keywords have your brand in the top 10 results.
How to report it: A trend chart of share of search over the last 3-6 months, with a comparison of average position for the category’s 5-10 most important keywords.
Warning sign: A sustained drop in share of search is an early warning sign of deteriorating positioning that will affect organic revenue in the following weeks or months. It’s the most valuable “leading indicator” for detecting problems before they impact sales.
KPI #6: LTV / CAC Ratio (for the D2C channel)
What it measures: The relationship between the total value a customer generates over their relationship with the brand (LTV - Lifetime Value) and the cost of acquiring that customer (CAC - Customer Acquisition Cost).
Why it’s the most important D2C channel KPI: In the D2C channel, the first order is rarely profitable on its own. The business model relies on the customer coming back to buy multiple times, and on accumulated LTV widely exceeding the CAC of acquiring them. If the LTV/CAC ratio is below 3, the D2C business model is in trouble.
How to calculate it:
LTV = Average order value × Annual purchase frequency × Average customer relationship duration (in years) × Product gross margin
CAC = Total marketing and sales spend in the period / Number of new customers acquired in the periodBenchmarks:
- LTV/CAC < 2: The D2C channel is destroying value. Urgent review of acquisition or retention needed.
- LTV/CAC 2-3: Transition zone. Sustainable but tight.
- LTV/CAC 3-5: Healthy range for most categories.
- LTV/CAC > 5: Excellent. The D2C channel is a high-value asset.
How to report it: LTV/CAC is a trend KPI (it takes months or years to be affected by operational changes) and a segment KPI (the ratio varies significantly by acquisition channel, product category and customer cohort). Reporting it by cohort (customers acquired in Q1 2024, Q2 2024, etc.) lets you see whether more recent campaigns are bringing in better- or worse-quality customers than previous ones.
KPI #7: Operational Platform NPS (Customer Experience Score)
What it measures: A synthesis of consumer experience metrics: average seller rating on the marketplace, claims rate, returns rate, percentage of positive reviews and, where it exists, the NPS from an in-house post-purchase satisfaction survey.
Why it’s seventh and not first: Operational NPS is the business’s guardrail. You can grow revenue in the short term at the expense of the customer experience: aggressive prices that create expectations the product doesn’t meet, promised delivery times that aren’t kept, poor claims management. But that strategy destroys eCommerce’s most valuable asset: consumer trust and seller reputation.
Customer Experience Score components:
- Average product rating (marketplace reviews): target > 4.3 stars.
- Claims rate (on MercadoLibre): target < 0.5%.
- Returns rate due to unmet expectations: target varies by category, but a rising rate is always a warning sign.
- Response time to inquiries: target < 24 hours.
How to report it: A dashboard with experience indicators consolidated into a “traffic light” (green/yellow/red for each metric) and the trend over the last 3 months. Include the main dissatisfaction themes extracted from negative review analysis and support tickets.
Warning sign: Any downward trend in experience metrics should be treated as urgent, not as information for the next report. Marketplace reputation is an asset that takes months to build and can deteriorate in weeks.
The ideal report structure: how to present these 7 KPIs
A good agency report has three layers:
Layer 1 - Executive Summary (1 page): Status of the 7 KPIs vs. target. Traffic light for each KPI (green/yellow/red). The 3 most important things that happened in the period. The 3 priority actions for the next period.
Layer 2 - Deep Dive by KPI (2-3 pages): For each KPI, the period’s number, the historical comparison, the relevant context (why did it go up or down?), and the recommended action.
Layer 3 - Thematic analysis (1-2 pages): A specific topic in depth each month: competitor analysis in a category, diagnosis of a specific channel, voice-of-the-consumer analysis, evaluation of a specific campaign.
The guiding principle: The report should be readable in 10 minutes by a director who doesn’t live eCommerce day-to-day, and it should always end with clear actions: what’s going to be done differently next period as a result of this report’s insights.
Conclusion: KPIs are a trust contract
The 7 KPIs presented in this article aren’t the only ones that matter. There are dozens of relevant metrics in a complex eCommerce operation. But these are the ones that, in our experience, best balance completeness (they cover the business’s most critical aspects), actionability (each one can connect to specific decisions), and communicability (they can be presented to leadership without needing a technical glossary).
An agency that reports these 7 KPIs consistently, with context and with clear recommendations, is fulfilling its role as a strategic partner, not just a service provider.
A brand that demands these 7 KPIs from its agency is exercising its role as leader of the digital channel, not just as a client.
Which of these 7 KPIs does your agency currently report? Is there one you consider critical that you’re not measuring? Tell us in the comments. If you want a template of the reporting dashboard we use internally with our clients, write to us and we’ll send it over.
By Matías Poso, CEO at Balloon Group a Fastforward AI Company.