Purchase frequency
How often the average active customer buys.
01 What it is
Why anyone looks at this number
How often the average active customer buys.
It is the quiet half of growth. Getting existing customers to buy one more time a year usually costs a fraction of winning the equivalent revenue in new logos.
02 The formula
How it is worked out
Purchase frequency = orders_in_period ÷ active_customers grain : year × segment unit : orders per customer per period source : Billing
Count orders, not lines or deliveries. A single order split into three deliveries is one purchase decision, and mixing the two triples the apparent frequency.
03 Worked example
The same number, with real inputs
| Orders in the year | 12,720 |
| Active customers | 3,180 |
| Calculation | 12,720 ÷ 3,180 |
| Result | 4.0 orders per customer |
One extra order per customer per year is 3,180 orders. At the average order value that is worth more than a 10% rise in new customer acquisition.
04 What moves it
Four things that actually change this number
Range relevance
How much of what they buy you actually sell.
Replenishment cycle
Order size against their consumption rate.
Contact cadence
Whether anyone speaks to them between orders.
Channel friction
Self-serve reordering raises frequency more than most campaigns.
05 Where the number lives
The system, the record and the fields
| System of record | Key record | Fields you need |
|---|---|---|
| Billing | Order joined to Customer | order_date, customer_id, order_value, channel |
Count orders, not lines or deliveries. A single order split into three deliveries is one purchase decision, and mixing the two triples the apparent frequency.
06 How it goes wrong
Three ways this metric misleads people
Averaging over a mixed base
Weekly buyers and annual buyers average into a meaningless middle.
Fix: Segment by buying pattern before averaging.Counting deliveries as orders
Split deliveries inflate frequency and understate order value.
Fix: Count the purchase decision.Ignoring the interval
Frequency hides whether the gap between orders is lengthening.
Fix: Track the median interval as well; it moves earlier.08 Questions
Frequently asked
Is frequency or basket size the better lever?
Frequency usually, because it is a habit rather than a single decision. Basket size tends to move once, then plateau.
How do we spot a customer about to lapse?
By their own interval, not the average. A customer who normally orders every three weeks and has not ordered in seven is the signal — a global rule would miss it entirely.
One definition, everywhere it is used
SCIKIQ stores this metric once and serves it to every dashboard, board pack and agent that asks.