Attach rate
How often a service, warranty, accessory or add-on is sold alongside the product it belongs to.
01 What it is
Why anyone looks at this number
How often a service, warranty, accessory or add-on is sold alongside the product it belongs to.
Attached items usually carry far higher margin than the product that pulls them through. A point of attach rate is often worth more than a point of price, and it costs nothing to acquire.
02 The formula
How it is worked out
Attach rate = orders_containing_the_attached_item ÷ eligible_orders grain : month × product family × channel unit : percentage source : Order lines, joined to the product hierarchy
It needs a product hierarchy that knows which SKU is primary and which is an attachment, and which orders were even eligible. Without that, the calculation is a hand-maintained list of SKU codes that breaks with the next catalogue release.
03 Worked example
The same number, with real inputs
| Eligible orders | 18,700 |
| Orders with a service plan | 4,120 |
| Gross profit per plan | €110 |
| Calculation | 4,120 ÷ 18,700 |
| Result | 22.0% |
Five points of attach is 935 more plans on the same hardware sales — about €103k of gross profit that requires no additional demand.
04 What moves it
Four things that actually change this number
Point of sale prompt
Whether the add-on is offered at all, and when.
Channel
Assisted sales attach far more than self-serve, consistently.
Bundling and pricing
An attachment priced as a percentage of the product behaves differently.
Eligibility rules
Which products can carry the attachment, kept current.
05 Where the number lives
The system, the record and the fields
| System of record | Key record | Fields you need |
|---|---|---|
| Order lines, joined to the product hierarchy | Order line joined to Product and Product family | order_id, sku, line_type, primary_sku, family_id, eligible_flag, line_margin |
It needs a product hierarchy that knows which SKU is primary and which is an attachment, and which orders were even eligible. Without that, the calculation is a hand-maintained list of SKU codes that breaks with the next catalogue release.
06 How it goes wrong
Three ways this metric misleads people
Ineligible orders in the denominator
The rate looks low everywhere and no team believes it.
Fix: Define eligibility in the product hierarchy and count only those orders.Rate without margin
Attach is chased on the cheapest add-on rather than the most valuable one.
Fix: Report attach rate and gross profit per attachment together.Blending assisted and self-serve
A channel mix shift looks like a performance change.
Fix: Report by channel; the coaching action only exists in one of them.08 Questions
Frequently asked
What counts as an eligible order?
One containing a product the attachment can legitimately be sold with. Getting this rule into the product hierarchy, rather than a spreadsheet, is most of the work of this metric.
Is a high attach rate always good?
Not if it is driven by attachments customers later cancel or claim against. Read it next to cancellation and return rates, or you are measuring a sale rather than a value.
One definition, everywhere it is used
SCIKIQ stores this metric once and serves it to every dashboard, board pack and agent that asks.