Attach Rate

Attach rate is the percentage of transactions that include a specific add-on product alongside a primary item — mixers attached to spirits, cups attached to ice, batteries attached to electronics. Originally an electronics-retail term, it's now standard across categories. A 40% attach rate for tonic-with-gin means four of every ten gin transactions also include tonic.

How it works

Operators query the POS for transactions containing the primary SKU, then check which of those also contain the candidate add-on. Attach rate = co-purchase count / primary count. Track it by store, by day-part, by season. Run the same calculation for each candidate add-on to find the strongest natural pairings.

Attach data is also a planning input — pairings with high attach but low display proximity are obvious merchandising fixes.

Why it matters for independent retailers

Attach rate turns vague "we should sell more mixers" into a precise number. A liquor store owner who sees 12% gin-tonic attach when the wine-shop average is 28% knows there's a specific lift opportunity in plain sight.

The follow-up actions are concrete: move tonic next to gin, add a cross-sell prompt on the kiosk, train weekend staff to ask the question. Each one is testable against the attach metric.

Related terms

• Retail Cross-Sell — what drives attach rate
• Basket Size — outcome metric
• Retail Upsell — vertical counterpart
• Inventory-Aware Recommendation — programmatic delivery of attach pairings

See also

• Remi product page — Remi surfaces attach pairings in conversation
• Liquor Stores — strong attach economics