What it means
At its simplest, e-commerce is a shop where the shelves are a website and the till is a payment gateway (the service that authorises a card payment and passes the money on). The business still buys stock, prices it, sells it and delivers it, but almost every step is measurable in a way a high street shop's is not.
That measurability is the main commercial difference. An online retailer knows how many people arrived, what share of them bought, what they spent on average and what it cost to acquire them, and it can change price or presentation the same afternoon.
The usual model splits into channels and segments. Business-to-consumer selling covers most retail sites, business-to-business e-commerce covers trade portals and wholesale ordering systems, and marketplaces sit in between by hosting third-party sellers in return for a commission.
The financial anatomy of an online order is consistent enough to plan with: revenue, then cost of goods, then payment processing fees, then picking, packing and shipping, then the marketing cost of finding the customer, and finally returns. Returns are the line most newcomers underestimate, since a 20% return rate in fashion effectively means one order in five earns no margin but still incurs shipping both ways.
The most important nuance is the difference between growth and profitable growth. Paid advertising can buy almost unlimited traffic, so an e-commerce business that does not track contribution margin per order and customer acquisition cost can scale revenue quickly while losing more money on every additional sale.
In practice
Real-world examples.
Example
A specialist tea merchant moves from three market stalls to an online shop and finds that a 1.8% conversion rate on 90,000 monthly visits produces more orders than all three stalls combined. The trade-off is that packaging and courier costs now consume 14% of revenue, a line that barely existed before.
Example
An industrial fastener distributor puts its 40,000-item catalogue online for trade customers. Order value per customer barely changes, but the cost to serve falls sharply because customers place their own orders instead of phoning a sales desk.
Example
A footwear brand launches direct-to-consumer sales alongside its wholesale business. Gross margin per pair roughly doubles, though a 25% return rate and higher marketing spend mean the direct channel only becomes more profitable than wholesale in its second year.
Formula
Calculation
Online revenue = Visits x Conversion rate x Average order value. Contribution = Revenue - Cost of goods - Payment and fulfilment costs - Marketing.
Northbeam Supply, an online homeware retailer, has one month of trading to assess.
Visits = 400,000
Conversion rate = 2.5%
Orders = 400,000 x 0.025 = 10,000
Average order value = $85
Revenue = 10,000 x $85 = $850,000
Cost of goods at 45% of revenue = $382,500
Payment fees and fulfilment at 12% of revenue = $102,000
Marketing spend = $170,000, which is 20% of revenue
Contribution = $850,000 - $382,500 - $102,000 - $170,000 = $195,500
Contribution margin = $195,500 / $850,000 = 23%. Marketing of $170,000 across 10,000 orders is a customer acquisition cost of $17 per order, against a contribution of $36.55 before marketing, so each order pays its way; if acquisition cost rose to $40, growth would start destroying value.Case study
Seen in the real world.
The following is an illustrative and entirely fictional example. Copperleaf Kitchenware grew online sales from $2,000,000 to $9,000,000 in two years and the founders assumed profitability would follow the volume. It did not, and the business burned $1,300,000 of cash over the same period.
A channel-level review found the cause. Sales from repeat customers and organic search carried a contribution margin of 31%, while sales bought through broad paid advertising carried 4% once acquisition cost, returns and free delivery were charged to them, and the paid channel had grown fastest because it was the easiest to scale.
Copperleaf capped paid spend at a contribution-positive acquisition cost, introduced a $6 delivery charge below a $60 basket, and shifted budget into email and a loyalty offer aimed at second purchases. Revenue growth slowed to about 15% a year in this illustrative scenario, but the business became cash generative within two quarters.
Watch out
Common mistakes.
- Judging performance on revenue growth alone. Paid traffic can buy revenue at any price, so growth without contribution margin per order tells you almost nothing about the health of the business.
- Leaving returns out of the margin calculation. Return shipping, inspection, repackaging and write-offs can turn an apparently profitable category into a loss-making one.
- Treating the platform fee as the only cost of selling on a marketplace. Advertising within the marketplace, fulfilment fees and price competition usually cost more than the headline commission.
Questions
People also ask.
What conversion rate should an online shop expect?
It varies widely by category, but many retail sites sit somewhere between 1% and 3%, with repeat-heavy and subscription models running higher.
Is a marketplace better than my own website?
A marketplace brings traffic you do not have to buy, while your own site keeps the customer relationship and the data, so many businesses run both and compare contribution by channel.
How does e-commerce change working capital?
Stock still has to be bought ahead of sale, but card payments usually settle within days rather than the 30 to 60 days trade customers take, so cash conversion is often faster than in wholesale.
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