Most e-commerce dashboards are built around what platforms report rather than what the business needs. Meta reports ROAS, Google reports conversions, Shopify reports sessions. None of them report whether you made money this month. The list below is what we track for clients, roughly in order of how often it changes a decision.
Profit metrics (the ones that matter most)
1. Contribution margin
Revenue − COGS − shipping & fulfilment − payment fees − marketing spend − returns cost. The number that says whether growth is worth having. Track weekly, by channel where possible. A UK DTC brand doing well runs 15–30% contribution margin after marketing.
2. Gross margin after returns
Gross margin is meaningless in fashion or footwear until returns are netted. Track returns rate by category and apply it. UK fashion returns run 20–40%; consumables under 3%.
3. MER (Marketing Efficiency Ratio)
Total revenue ÷ total marketing spend, all channels, from Shopify. Immune to attribution arguments. If MER is flat while platform ROAS is rising, platforms are claiming credit for existing demand. Healthy ranges: 4–8× for established brands; 2–3× while aggressively acquiring.
4. New-customer CAC
Marketing spend ÷ first-time customers (Shopify's "first order" flag or Klaviyo's first purchase). Blended CAC hides that most spend should be buying new customers. Track paid-only CAC too.
Customer metrics
5. Repeat purchase rate (90 / 180 / 365 days)
Share of customers who order again within the window, by acquisition cohort. Consumables: 30–50% at 180 days is good. Considered purchases: 10–20%. If BFCM cohorts repeat at half the rate of others, your discounting is buying the wrong customers.
6. LTV : CAC
12-month contribution margin per customer ÷ CAC. Under 2:1 you are subsidising customers; 3:1+ is sustainable. Compute by channel — Meta and Google cohorts often differ substantially.
7. Payback period
Months until a cohort's cumulative contribution margin exceeds its CAC. Under 3 months lets you reinvest fast; over 9 months needs cash you may not have.
8. Email/SMS revenue share
Klaviyo-attributed revenue ÷ total revenue (use a conservative attribution window, e.g. 3-day click). 25–40% is healthy; under 15% means the list or flows are underbuilt. See our Klaviyo audit.
Site and funnel metrics
9. Conversion rate — by device and channel
A blended 2.5% hides a 4% desktop and 1.6% mobile. UK Shopify benchmarks: 1.5–3.5% overall; consumables and repeat-heavy stores higher.
10. Average order value and items per order
AOV moves with mix and promotions; items per order tells you whether bundling and thresholds are working. Our AOV guide has the levers.
11. Checkout completion rate
Orders ÷ sessions that reached checkout. 45–55% is healthy. The single most actionable funnel number.
12. Site speed (LCP on mobile)
Not a business metric, but it moves every one above it. Under 2.5s. Track in Search Console's Core Web Vitals report monthly.
Channel metrics (for optimisation, not for the board)
13. Platform ROAS / CPA
Use for day-to-day bidding decisions inside Meta and Google. Never for judging the channel's contribution — that is MER and new-customer CAC.
14. Organic revenue and non-brand clicks
From GA4 (organic channel revenue) and Search Console (non-brand queries). Brand search tells you about advertising; non-brand tells you about SEO.
15. Marketplace share and fees
If you sell on Amazon, eBay or OnBuy: revenue share, net margin after fees and ads per channel. Marketplaces frequently show "growth" that is margin-negative once FBA and advertising are deducted.
Metrics to stop reporting
- Impressions and reach — inputs, not outcomes.
- Platform ROAS in the weekly summary — replace with MER.
- Total sessions — replace with sessions by channel and conversion.
- Email open rate — unreliable since Apple Mail Privacy; use click rate and revenue per recipient.
- Follower counts — nobody has ever paid a supplier in followers.
How to actually track this
Shopify gives you revenue, orders, AOV, first-time vs returning and checkout funnel. GA4 gives you channel conversion and organic revenue (once implemented properly — see GA4 for Shopify). COGS and fulfilment costs come from your accounting or a margin app. Ad spend from each platform. Pull all of it into one Looker Studio dashboard with a weekly view — our Looker Studio guide shows the build. The one-page version for owners: contribution margin, MER, new-customer CAC, repeat rate, conversion rate, AOV. Everything else is for the operators.
If a metric cannot change a decision this week, it belongs in an appendix, not a dashboard.
Frequently asked questions
What is a good MER for an e-commerce brand?
Marketing Efficiency Ratio (total revenue ÷ total marketing spend) of 4–8× is typical for established UK DTC brands; 2–3× is acceptable while investing heavily in new-customer acquisition, provided LTV:CAC supports it.
What is a good conversion rate for a Shopify store in the UK?
1.5–3.5% overall is typical; consumables and repeat-purchase stores can exceed 4%. Always split by device — mobile usually converts at roughly half the desktop rate.
Why is ROAS a bad primary metric?
Platform ROAS relies on each platform's own attribution, which overlaps and overstates, and it ignores margin, returns and whether the customer was new. Use it for in-platform optimisation only; judge channels on MER, contribution margin and new-customer CAC.
How do I calculate customer lifetime value for e-commerce?
Sum contribution margin (not revenue) per customer over a fixed window — typically 12 months — by acquisition cohort. Compare to CAC for that cohort; 3:1 or better is sustainable.
Want this done for you?
Groweyo builds and runs the full e-commerce growth stack for UK brands — Shopify, paid media, Klaviyo, marketplaces and analytics. Free 30-minute consultation, no pitch deck.
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