E-commerce KPIs: The Numbers Every Store Owner Should Watch

The most useful ecommerce KPIs, or key performance indicators, are the few numbers that show whether your store is attracting the right visitors, turning them into customers, making a profit on each order and bringing customers back. Most store owners have access to far more data than they can use. Analytics tools, platform reports, advertising dashboards and marketplace statistics all compete for attention. The risk is spending hours looking at figures without ever changing anything. A short, well-chosen set of KPIs, reviewed regularly and read together, gives a clear picture of the business and points to the next decision.

This guide groups the essential numbers by what they tell you, explains common traps and suggests a simple weekly and monthly routine.

Sales and revenue KPIs

Start with the headline figures that show how much the store is selling.

• Revenue: total sales, ideally shown before and after returns and discounts.
• Orders: the number of completed orders.
• Average order value: revenue divided by orders. It shows how much customers spend each time.
• Units per order: how many items customers buy together.

Revenue is the figure everyone watches, but it rarely explains itself. A rise could come from more visitors, a better conversion rate, larger baskets or higher prices. The KPIs in the following sections show which.

Always compare revenue with a sensible baseline. Comparing December with November will mislead a seasonal business; comparing with December last year is far more useful.

Break revenue down by category and by your top products as well. A healthy total can hide a best seller that is quietly declining, or a single product carrying the whole store. Knowing which products drive sales helps you protect stock, marketing and margin where they matter most.

Traffic and acquisition KPIs

These show how many people visit and where they come from.

• Sessions or visitors: how much traffic the store receives.
• Traffic by channel: organic search, paid search, social, email, referrals and direct.
• New versus returning visitors: how well you attract new people and bring people back.
• Customer acquisition cost: marketing spend divided by the number of new customers it brought.
• Return on advertising spend: revenue from adverts compared with what they cost.

Quality matters more than quantity. A channel that brings many visitors who never buy is less valuable than a smaller channel full of buyers. Always look at traffic alongside conversion and order value by channel.

Be careful with acquisition figures reported by advertising platforms. Each platform tends to take credit for sales it influenced, so adding their figures together often produces more sales than the store actually received. Use your own order data as the reference point, and compare channels using a consistent method over time.

Engagement figures help judge quality too. Google explains how engagement rate and bounce rate are measured in Google Analytics 4, which helps when comparing channels.

Conversion KPIs

Conversion KPIs show how well the store turns visitors into customers.

Look at these as a funnel. If add-to-basket rate is healthy but checkout completion is low, the problem lies in checkout: delivery costs, forms or payments. If few visitors add anything to the basket, look at product pages, prices and traffic quality. Our guides to improving conversion rate and reducing cart abandonment explain what to do at each stage.

Always split conversion by device. Phones usually bring the most traffic but convert less, and a widening gap often reveals a mobile problem. Split by new and returning visitors too, since returning visitors usually convert better and a change in the mix can move the overall rate without anything on the site changing.

Profit and margin KPIs

Revenue can grow while profit falls. These KPIs make sure growth is worthwhile.

• Gross margin: revenue minus the cost of goods sold, as a share of revenue.
• Contribution per order: what each order leaves after product cost, delivery, payment fees, packaging and returns.
• Discount rate: how much revenue is given away through discounts and promotions.
• Return rate: how many orders or items come back, and the cost of handling them.
• Marketing cost per order: total marketing spend divided by orders.

Contribution per order is one of the most useful figures for a store owner. It shows whether an average order actually makes money once the costs that vary with each order are included. If it is thin, growing volume will not fix the business. Calculate it by channel and by product category too, because a busy channel or popular category can turn out to be the least profitable once delivery, returns and discounts are counted.

Customer and retention KPIs

Repeat customers are usually the most profitable. These KPIs show whether customers come back.

• Repeat purchase rate: how many customers place a second order within a given time.
• Time between orders: how long customers typically wait before buying again.
• Customer lifetime value: the profit a customer brings over time.
• Revenue from returning customers: the share of sales from people who have bought before.
• Customer satisfaction: review scores, survey results and complaint levels.

Compare customer lifetime value with acquisition cost to judge how much you can afford to spend on marketing. Our guides to customer lifetime value and customer retention explain both in depth.

Operations and fulfilment KPIs

Customers judge the store on delivery as much as on the website. Operations KPIs show whether you are keeping your promises.

• Time to dispatch: from order to the parcel leaving the warehouse.
• On-time delivery rate: deliveries arriving by the promised date.
• Order accuracy: orders sent without wrong or missing items.
• Stock availability: how often best sellers are out of stock.
• Customer service contacts per order: a rising figure often signals a problem elsewhere.

Stock availability deserves particular attention. Out-of-stock best sellers lose sales quietly, because the lost orders never appear in reports. Track how many days each top product was unavailable, and how much traffic its page received while it was out of stock. Our guide to inventory management explains how to keep the right stock in the right place.

Site health KPIs

Technical problems can undermine every other number. A few site health KPIs act as early warnings.

• Page speed: loading and responsiveness on key templates, especially on phones. Google's Core Web Vitals provide a standard way to measure it.
• Uptime: how often the store is available, especially during busy periods.
• Error rates: failed pages, failed payments and checkout errors.
• Search visibility: impressions and clicks from search engines for important pages.

When a commercial KPI falls suddenly, check site health first. A broken payment method or a slow release often explains a drop faster than any marketing analysis. Keep a simple log of releases, campaigns and price changes alongside your KPIs, so you can match a change in the numbers to its likely cause. Our guide to Core Web Vitals for online stores explains how speed affects sales.

Reading ecommerce KPIs together

Single figures mislead. Combining them tells the story.

• Revenue up, conversion down: more traffic is arriving but a smaller share buys. Check whether the new traffic is well targeted.
• Revenue up, contribution down: discounts, delivery costs or returns may be eating the gain.
• Conversion up, average order value down: a promotion may be attracting smaller orders.
• Repeat rate down, complaints up: a delivery or product quality problem may be driving customers away.

Look for the combination that explains the change before deciding what to do, rather than reacting to the first figure that moves. Watch for tracking changes as well. A new consent banner, analytics update or checkout change can shift figures without any change in customer behaviour. Our guide to ecommerce analytics with GA4 covers reliable tracking.

A weekly and monthly review routine

KPIs only help if someone looks at them and acts. A simple routine works better than an elaborate dashboard nobody opens.

Weekly, in fifteen minutes

1. Revenue, orders and average order value against the same week last year.
2. Conversion rate by device.
3. Traffic and sales by main channel.
4. Stock of best sellers.
5. Any operational issues: dispatch delays, complaints, payment problems.

Monthly, in an hour

1. Contribution per order and gross margin.
2. Acquisition cost and return on spend by channel.
3. Repeat purchase rate and returning customer revenue.
4. Return rates by product and reason.
5. Site speed and search visibility for key pages.

End each review with no more than three actions, each with an owner. Then check at the next review whether they made a difference.

Share a short summary with the wider team. When everyone sees the same few numbers, conversations about priorities become simpler and decisions are based on evidence rather than opinion.

Frequently asked questions

Want a clear dashboard of the numbers that matter for your store? Talk to our team about reporting that connects sales, marketing and operations.