E-commerce Fundamentals
Most digital marketing leads to an online sale — so you need to understand the store models, the product page, the checkout, and the numbers that run them.
What you will learn
- Name the main online store models (D2C, marketplace, etc.)
- Describe the parts of a product page and checkout
- Read the core e-commerce KPIs like conversion rate and cart abandonment
Where the click usually ends: a sale
E-commerce simply means buying and selling things over the internet. It matters to marketers because most digital marketing eventually points at an online store — your ads, emails and SEO all try to drive a sale. The flagship paid certificates pair marketing with e-commerce for exactly this reason. So let us learn how an online store actually works.
The main online store models
There is no single kind of online store. Here are the four models you will meet most often.
| Model | What it means | Example |
|---|---|---|
| D2C (Direct-to-Consumer) | A brand sells straight to buyers on its own website | A tea brand selling on freshleaf.in |
| Marketplace | A shared platform where many sellers list goods | Amazon, Flipkart, Meesho |
| B2B | A business sells to other businesses | A wholesaler supplying shops |
| Subscription | Customers pay regularly for repeat delivery | A monthly coffee or tiffin box |
Many businesses use more than one — a tea brand might sell D2C on its own site and list on the Amazon marketplace to reach more people.
The two pages that close the sale
Two pages do almost all the selling work in any store: the product page and the checkout.
- The product page is where a shopper decides to buy. It needs clear photos, the price, a short benefit-led description, reviews, and one obvious “Add to cart” button.
- The cart holds the items the shopper picked. The checkout is the final step where they enter address and payment. Every extra field or surprise cost here loses sales.
Here is the typical path a shopper walks, from landing to a confirmed order.
Product page -> Add to cart -> Cart -> Checkout -> Payment -> Order confirmedNote: Each arrow is a place a shopper can drop off. The biggest leak is usually between Cart and Order confirmed — people add items, then abandon at checkout. Shortening this flow (fewer form fields, guest checkout, trusted payment) directly lifts sales.
The e-commerce KPIs you must know
Online stores track a few numbers beyond the ad metrics you already know.
| KPI | What it measures | Plain meaning |
|---|---|---|
| Conversion rate | Buyers / visitors | What share of visitors actually buy |
| AOV (Average Order Value) | Revenue / number of orders | How much an average order is worth |
| Cart abandonment rate | Carts left / carts started | Share of shoppers who add items but do not buy |
A worked example
A D2C clothing store gets 5,000 visitors in a month. 150 of them buy, placing orders worth ₹1,80,000 in total. Of everyone who added something to a cart (500 carts), 350 left without paying. Let us read the numbers.
Conversion rate = buyers / visitors = 150 / 5000 = 3%
Average Order Value = revenue / orders = 180000 / 150 = Rs 1200
Cart abandonment = abandoned / started = 350 / 500 = 70%Note: A 3% conversion rate is healthy for e-commerce. The average order is Rs 1200. But a 70% cart abandonment rate is a giant, common leak — 70 out of every 100 shoppers who were ready to buy walked away at the cart. Fixing checkout friction here would lift sales more than any new ad.
Tip: Two easy ways to raise AOV (the value of each order): offer free shipping above a threshold (“free delivery over ₹999”) and suggest a small add-on at checkout. Both nudge the order value up without finding a single new customer.
Watch out: Driving more traffic to a broken store wastes money. If your conversion rate is very low or cart abandonment is very high, fix the product page and checkout first — otherwise every rupee of ad spend just pours more people into a leaky bucket.
Q. A store had 4,000 visitors and 120 of them bought. What is its conversion rate?
✍️ Practice
- Match each store model to an example: D2C, marketplace, subscription, B2B.
- A store had 2,000 visitors, 80 orders worth ₹96,000. Calculate its conversion rate and average order value.
🏠 Homework
- Visit any online store you like and write down: its store model, three things its product page does well, and one thing about its checkout that could lose sales.