Customer analytics guide
Shopify cohort analysis: a practical guide
A cohort analysis shows whether the customers you win today come back as often as the ones you won last year. This guide explains how to build one from your Shopify orders, how to read it and what to change when the numbers move.
Written by Malick Alexandre Sarr, co-founder of Avantages. Published on . About 8 minutes to read.
What is a Shopify cohort analysis?
A Shopify cohort analysis groups customers by the month of their first order and then tracks how many of them order again in each month that follows. Each group is a cohort. Comparing cohorts shows whether retention is improving, flat or getting worse, which a single store-wide number cannot show.
For example, the January cohort is every customer whose first order was in January. If 1,000 people joined in January and 90 of them ordered again in February, the January cohort’s month 1 retention is 9%.
Why cohorts beat a single repeat purchase rate
A store-wide repeat purchase rate mixes customers you won five years ago with customers you won last week. When you acquire many new customers, the rate drops even if they behave exactly like earlier customers, because they have not had time to come back yet. When acquisition slows, the rate rises even if loyalty is falling.
Cohorts remove that noise. Each customer is compared only with people who started at the same time, so a change in a cohort’s curve reflects a real change in behaviour, such as a new product, a different discount or a shift in which channel brought them in.
How to read a cohort retention table
A retention table has one row per cohort and one column per month since the first order. Each cell shows the share of the cohort that placed an order in that month. Reading across a row shows how one cohort behaves over time. Reading down a column compares cohorts at the same age, which is the comparison that matters.
The table below uses illustrative numbers to show the shape, not benchmarks. Retention drops sharply after the first month and then flattens. The level where the curve flattens is your loyal base: the customers who keep buying without being won again.
| First-order month | New customers | Month 1 | Month 2 | Month 3 | Month 6 |
|---|---|---|---|---|---|
| January | 1,200 | 9% | 6% | 5% | 4% |
| February | 1,050 | 10% | 7% | 5% | 4% |
| March | 1,400 | 8% | 5% | 4% | Not yet |
| April | 1,600 | 6% | 4% | Not yet | Not yet |
What the example tells you
Month 1 retention fell from about 10% in February to 6% in April, while the number of new customers grew. A store-wide repeat rate would hide that drop behind the larger April cohort. The next question is what changed for April buyers: a new ad audience, a heavier discount, a different best-selling first product or a delivery problem.
Cohorts do not answer that question on their own. Split the same table by acquisition channel, first product or discount code, and the cause usually becomes visible within a few rows.
How to build a cohort analysis from Shopify orders
You can build a basic cohort table in a spreadsheet from a Shopify order export. The steps below assume one row per order with a customer ID, an order date and an order status.
- Remove test orders, cancelled orders and orders without a customer ID, such as some guest checkouts, so each row belongs to a real customer.
- For each customer, find the date of their first order and turn it into a month. That month is the customer’s cohort.
- For every later order, count the months between the order and the customer’s first order. An order in the following calendar month is month 1.
- Count the distinct customers who ordered in each cohort and month, and divide by the number of customers in the cohort.
- Show the result as percentages, leave cells empty when a cohort is not old enough yet, and keep the cohort size next to each row.
Monthly retention or cumulative retention?
Monthly retention counts customers who ordered in a given month. It is useful for spotting when people come back, which helps you time a second-purchase email. Cumulative retention counts customers who have ordered again at any point up to that month. It always rises and makes it easier to compare cohorts at a glance.
Most teams look at cumulative retention to judge whether a cohort is healthy and at monthly retention to plan campaigns. Whichever you choose, use the same definition every time so cohorts stay comparable.
Common cohort analysis mistakes
- Comparing a young cohort with an old one. A cohort that is three months old cannot be judged on six-month retention yet.
- Using calendar months instead of months since the first order, which mixes customers who are at different stages.
- Counting the first order as a repeat order, which makes every cohort look perfect in month 0.
- Ignoring cohort size. A cohort of 40 customers can swing by several points because of two people, so treat small cohorts as noise.
- Ignoring seasonality. Customers won during a big sale often come back less than customers who paid full price, so compare a sale cohort with the same sale last year.
Turning cohort insights into decisions
Cohort analysis is useful when it changes a decision. Three decisions it informs well are where to spend on acquisition, when to send retention campaigns and which products to lead with.
- Compare cohorts by acquisition channel to see which channel brings customers who come back, not only customers who buy once.
- Look at the month in which most repeat orders happen and send your second-purchase flow just before it.
- Compare cohorts by first product. Products that bring loyal customers deserve a bigger share of your ad budget than their first-order revenue suggests.
- Pair cohorts with RFM segments to see which of today’s customers are drifting away before they show up as lost in next quarter’s cohort table.
Cohort retention in AvantagesLive
Get your cohort table without the spreadsheet
Avantages builds the cohort retention table from your Shopify orders automatically and keeps it up to date every day. Each row follows one month of first-time buyers, and the daily AI briefing tells you when a new cohort starts to behave differently from the ones before it.
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