Marketing performance reporting for ecommerce can either be a crystal-clear decision system—or a weekly ritual of dashboards nobody trusts. The difference isn’t the BI tool, the chart style, or the number of tabs in your spreadsheet. It’s whether your reporting focuses on the handful of signals that truly explain growth: profitable demand, retention, and the operational reality of converting attention into revenue.
Ecommerce teams have more data than ever: platform analytics, ad dashboards, attribution tools, CRM, CDPs, and customer support systems. Yet many brands still make decisions based on “easy” metrics—impressions, clicks, follower growth, and blended ROAS—because those numbers are visible, immediate, and reassuring. Unfortunately, they can also be misleading.
This article breaks down marketing performance reporting for ecommerce into the KPIs that actually matter. You’ll learn what to track, how to structure reporting, which metrics to treat as supporting indicators (not goals), and how to avoid common traps. Along the way, you’ll see how to connect performance reporting to real business outcomes, so your weekly reports become a tool for confident decision-making instead of a post-mortem.
And yes—if you’re building a scalable system, you’ll also want a consistent methodology for ecommerce reporting across channels, markets, and product lines.
Why Ecommerce Marketing Reporting Is So Often Wrong
Most ecommerce reporting goes off the rails for three reasons:
- Misaligned goals
- Marketing reports often optimize for what platforms reward: spend, clicks, or “in-platform” conversions—rather than profitable growth.
- Attribution confusion
- The truth is that no single attribution model is perfect. Many teams treat attribution as an answer instead of a lens. The result is overconfidence in channel-level ROI and constant budget whiplash.
- Lack of business context
- Marketing doesn’t happen in a vacuum. Stockouts, shipping delays, pricing changes, site speed, and product assortment can all move conversion rates and revenue. Reports that ignore these variables encourage the wrong conclusions.
A strong reporting system doesn’t attempt to “prove” marketing is working. It helps you understand what’s happening, why it’s happening, and what to do next.
The Hierarchy: North Star KPIs vs Supporting Metrics
Before diving into specific KPIs, it helps to set a hierarchy. A good ecommerce reporting framework contains three layers:
1) Business outcomes (North Star)
These are metrics that matter to the company’s health:
- Revenue (with context)
- Gross margin and contribution margin
- Customer lifetime value (or LTV proxy)
- Repeat purchase rate / retention
2) Marketing efficiency metrics
These translate marketing activity into financial outcomes:
- CAC (Customer Acquisition Cost)
- MER (Marketing Efficiency Ratio)
- New customer revenue and share
- Incremental lift (when measurable)
3) Diagnostic metrics (supporting indicators)
These help you debug performance:
- CTR, CPC, CPM
- Landing page conversion rate
- Add-to-cart rate
- Email open rate
- Engagement metrics
The key rule: supporting metrics are not goals. They are indicators. Your reports should treat them like a doctor treats blood pressure—not as the outcome itself, but as a signal about what’s happening beneath the surface.
KPI #1: Contribution Margin (or Profit, Not Just Revenue)
If you’re still reporting only on revenue, you’re likely rewarding the wrong behavior. In ecommerce, revenue can be “bought” through heavy discounting, free shipping, or aggressive acquisition that brings low-quality customers.
A more realistic KPI is contribution margin—profit after variable costs. At minimum, your reporting should incorporate:
- Product margin (COGS)
- Shipping and fulfillment costs
- Payment processing fees
- Discounts and returns
- Marketing spend
Why it matters:
- It distinguishes high-revenue/low-profit campaigns from sustainable growth.
- It prevents “ROAS theater,” where revenue looks great but the business loses money.
If true contribution margin data is hard to access weekly, use a proxy:
- Revenue × average gross margin % – marketing spend – estimated variable costs
Even a simplified proxy is far better than ignoring profitability entirely.
KPI #2: MER (Marketing Efficiency Ratio)
MER = Total Revenue / Total Marketing Spend
MER is one of the most practical KPIs for ecommerce reporting because it helps you understand blended efficiency across channels. It’s not perfect—but it’s directionally powerful, especially in a world where attribution is messy.
Why MER matters:
- It reduces channel-by-channel arguments fueled by inconsistent attribution.
- It aligns performance reporting with business outcomes.
- It supports strategic budget decisions (scale vs efficiency) more effectively than ROAS alone.
How to report MER properly:
- Track MER weekly and monthly.
- Compare against targets tied to your margin structure.
- Break it down by:
- Product category
- Market/region
- New vs returning customer revenue
Important nuance: MER rises naturally during promotional periods and can dip during acquisition pushes. The point is not to chase the highest MER—it’s to know what range is sustainable for growth.
KPI #3: CAC (Customer Acquisition Cost) — But Done Correctly
CAC is essential, but many teams calculate it incorrectly.
A useful CAC definition for ecommerce:
- CAC = acquisition marketing spend / number of new customers acquired
“New customers” should be defined consistently (e.g., first-time purchasers). If you can, separate spend that primarily drives acquisition from spend that primarily drives retention.
How to make CAC actionable:
- Track CAC trends over time.
- Compare CAC against an LTV proxy (see below).
- Segment CAC by:
- Channel (with caution)
- Audience type (prospecting vs remarketing)
- Product category (especially if AOV differs)
CAC becomes dangerous when you treat it as a fixed number. It’s dynamic. It shifts with seasonality, competition, creative fatigue, and platform changes. Your report should emphasize trends and context—not a single “truth.”
KPI #4: New Customer Revenue and New Customer Share
Ecommerce brands often celebrate revenue growth without noticing they’re simply monetizing existing customers harder—until repeat demand slows and growth stalls.
Add these to your reporting:
- New customer revenue (absolute number)
- New customer share (new customer revenue as a % of total revenue)
- New customer count
Why it matters:
- It shows whether growth is driven by acquisition or retention.
- It helps forecast future revenue stability.
- It reduces the risk of “retention-only” growth that eventually plateaus.
This KPI is especially important when promotional strategies inflate returning customer purchases. Your report should clarify whether marketing is expanding the customer base or just squeezing the current one.
KPI #5: LTV (or an LTV Proxy You Can Actually Use)
True LTV takes time, and many teams avoid it because it’s complex. But you don’t need a perfect LTV model to make better decisions. You need a consistent one.
Options for LTV reporting:
- 90-day LTV (revenue or contribution margin per customer within 90 days)
- 6-month LTV (better for slower repurchase cycles)
- LTV proxy such as:
- AOV × average purchase frequency over a fixed window
- Contribution margin per customer over 90 days
Pair it with CAC:
- LTV:CAC ratio (or proxy ratio)
Why it matters:
- It tells you whether acquisition is sustainable.
- It helps justify investment in upper-funnel marketing.
- It keeps you from optimizing for short-term ROAS at the expense of customer quality.
A practical reporting habit: show LTV proxy by cohort (e.g., customers acquired in August vs September) and compare across channels or campaigns when possible.
KPI #6: Repeat Purchase Rate and Retention
Retention isn’t just a CRM team responsibility. It is a marketing outcome. Strong retention lowers the pressure on acquisition and stabilizes cash flow.
Core retention metrics for ecommerce reporting:
- Repeat purchase rate (percentage of customers who purchase more than once)
- Time to second purchase (median days)
- Customer retention by cohort (e.g., 30/60/90-day repeat)
Why it matters:
- It reveals whether marketing is attracting the right customers.
- It helps evaluate post-purchase flows, loyalty programs, and product satisfaction.
- It acts as an early warning system when customer quality drops.
If your product has a long repurchase cycle, consider alternative retention signals:
- Subscription retention
- Refill rate
- Reactivation rate (customers returning after inactivity)
KPI #7: Refund, Return, and Cancellation Rate
This is the KPI many marketing teams forget—until finance reminds them.
In ecommerce, returns and cancellations can silently destroy profitability and distort performance metrics. If you report on revenue without returns, you may scale campaigns that look good but generate expensive problems.
Track:
- Return rate (orders or revenue)
- Refund rate
- Cancellation rate
- Return rate by:
- Product category
- Campaign/promo
- Region
Why it matters:
- It protects contribution margin.
- It reveals mismatched expectations caused by creative, product pages, or audience targeting.
- It prevents “growth” that creates customer service overload.
For brands with high return risk (apparel, high-ticket items), this KPI belongs in every weekly marketing report.
KPI #8: Conversion Rate with Funnel Breakdowns
Conversion rate is not one number. It’s a system of micro-conversions.
Core funnel metrics:
- Sessions → product page views
- Product page views → add-to-cart
- Add-to-cart → begin checkout
- Begin checkout → purchase
Track these alongside:
- Mobile vs desktop conversion rate
- New vs returning visitor conversion rate
- Landing page conversion rate for key campaigns
Why it matters:
- It helps you diagnose whether performance issues are traffic quality, onsite UX, or offer-related.
- It identifies the leakiest step in the funnel so you know what to fix first.
A big reporting mistake is to treat conversion rate changes as a marketing problem. Sometimes the culprit is:
- Site speed
- Broken payment methods
- Inventory issues
- Confusing product variants
- Unexpected shipping costs
Your report should include a short “context notes” section to capture these operational variables.
KPI #9: AOV, Items per Order, and Discount Rate
Average Order Value (AOV) is a key driver of profitability and payback. But AOV alone can be deceptive if it’s driven by discounting.
Track:
- AOV
- Items per order
- Discount rate (or average discount per order)
- Revenue per visitor (RPV = revenue / sessions)
Why it matters:
- AOV helps explain why ROAS or MER changed.
- Discount rate tells you if growth is “real” or promo-dependent.
- RPV combines conversion rate and AOV into one powerful indicator.
A simple rule: if AOV is rising while discount rate is also rising, you may be training customers to wait for promos.
KPI #10: Payback Period (Especially for Growth-Stage Brands)
Payback period measures how long it takes to recover acquisition cost through profit.
A practical version:
- Payback period = days until contribution margin from a cohort exceeds CAC
Why it matters:
- It connects marketing to cash flow.
- It helps decide whether you can afford to scale acquisition.
- It makes growth strategy more concrete than “increase ROAS.”
If you can’t calculate payback precisely, use a payback proxy:
- CAC vs contribution margin within 30/60/90 days
This KPI is especially useful when you work with partners like Zoolatech, where marketing, analytics, and engineering can align on clean cohort tracking and lifecycle measurement.
Metrics to Stop Treating as “Success” (But Still Monitor)
Some metrics are useful—but only as diagnostics. Your report should include them in a secondary section, not at the top.
Examples:
- Impressions and reach
- CTR
- CPC and CPM
- Email open rate (privacy changes make it unreliable)
- Social engagement metrics
- Video view-through rate
Why they still matter:
- They can indicate creative fatigue, audience mismatch, or rising competition.
- They help explain why CAC or MER moved.
But they should never be the headline. A high CTR with poor conversion is not success—it’s misalignment.
A Reporting Template That Actually Drives Decisions
A strong weekly ecommerce marketing report can fit on 1–2 pages (or one dashboard view) if it’s structured correctly.
Section 1: Executive summary (5–8 bullet points)
Include:
- Revenue, contribution margin proxy, and MER vs last week and vs target
- New customer revenue and new customer count
- CAC trend
- One sentence on what changed and why
- 1–3 actions for next week
Section 2: Core KPI table (weekly + rolling 4-week)
Track:
- Revenue
- Contribution margin (or proxy)
- Marketing spend
- MER
- New customer count
- CAC
- Repeat purchase rate (or cohort indicator)
- Return/refund rate
- Conversion rate and RPV
Section 3: Channel and campaign insights (directional)
Instead of listing every campaign, focus on:
- Top 3 drivers of growth
- Top 3 drags on performance
- Notes on creative, audience, and offer tests
Section 4: Funnel diagnostics and site health
Include:
- Funnel step conversion rates
- Site speed and outage notes
- Inventory or shipping constraints
Section 5: Experiments and learning log
Track:
- What you tested
- What you learned
- What you’re doing next
This is how ecommerce reporting becomes an engine for continuous improvement instead of a weekly blame game.
Common Reporting Mistakes (And How to Avoid Them)
Mistake 1: Reporting only platform ROAS
Fix: Add MER and profitability context.
Mistake 2: Treating attribution as reality
Fix: Use attribution as a directional lens; validate with blended metrics and, when possible, incrementality testing.
Mistake 3: Ignoring customer mix
Fix: Always report new vs returning customer performance.
Mistake 4: No cohort view
Fix: Track customers acquired by week/month and monitor their behavior over time.
Mistake 5: Not tying performance to operations
Fix: Add a “context notes” field every week (pricing, inventory, shipping, site issues).
Final Thoughts: Reporting That Builds Confidence
The goal of marketing performance reporting for ecommerce isn’t to produce a beautiful dashboard. It’s to create a shared understanding of what’s happening in the business—and what decisions will improve outcomes.
If you track profitability (or a clear proxy), MER, CAC, new customer share, LTV proxies, retention, returns, conversion funnel health, and payback, you’ll have a reporting system that supports sustainable growth. Everything else becomes supporting evidence.
Whether you’re building your reporting stack in-house or partnering with a team like Zoolatech to improve data pipelines, tracking quality, and decision workflows, the principle stays the same: focus on KPIs that reflect reality, not just what platforms make easy to measure.