- Formula
- (Secondary units / primary units) x 100
- Unit
- % or ratio
- Models
- Hardware
No public benchmark exists for this metric yet. This is where Omega Point's proprietary data will fill in.
What it is
Attach rate measures how many secondary or accessory units are sold alongside each primary unit. Formula: (secondary units sold ÷ primary units sold) × 100, expressed as a percentage or ratio.
How to calculate it
Define the primary unit (e.g., a hardware device, a core product) and the secondary unit (e.g., an accessory, a software license, a service plan, a complementary product). Divide total secondary units sold in a period by total primary units sold in the same period. For multi-level attach (multiple accessories per device), the ratio can exceed 100%; for single-item accessories, it is bounded at 100% if only one can attach per primary.
Why it matters
For hardware and bundled product businesses, attach rate is the primary lever for improving unit economics. A hardware device sold at or near cost becomes profitable primarily through attached services, accessories, or content. Attach rate determines whether the total value per customer relationship is growing beyond the initial transaction. It also surfaces the effectiveness of cross-sell and bundling strategies: a low attach rate on a product with strong standalone demand signals a packaging or placement problem, not a demand problem.
How to read it
There is no credible published benchmark for attach rate that generalizes across hardware or bundled product categories. The metric is extraordinarily product-dependent: a consumer IoT device may attach software subscriptions at 30–40%, while a connectivity device like a broadband gateway may attach ancillary services above 90% simply because the product is nonfunctional without them. The occasional anecdote circulates (AT&T U-verse broadband attachment rates above 90% have been cited) but these are product-specific and not comparable.
Comparing your attach rate to external figures would be misleading without knowing the product type, pricing structure, and channel mix of the comparison. The meaningful comparison is your own attach rate over time, broken out by SKU, channel, and promotion type. Set targets based on your product's margin structure — what attach rate makes the unit economics work — rather than an external band.