Bundling slow movers with bestsellers: when it works and when it trains discount hunters
The bundle that works
A bundle works when the products belong together in the customer's mind, not just in the warehouse. A camera with a memory card, a skincare set with the cleanser and the moisturiser, a tool with the blades it needs: the customer buys the bundle because it is the complete purchase, and the price is lower than buying the pieces separately. The discount is the reason to buy the bundle. It is not the reason to buy the product.
The math has to work on the margin, not just on the revenue. A bundle that raises the order value by 20 dollars and costs 25 dollars in margin is a loss, even though the revenue went up. The calculation is the bundle margin against the margin of selling the bestseller alone, and the slow product's margin at clearance, not at full price. A slow product that would have been marked down 50 percent anyway is not worth full price in a bundle. It is worth its clearance value, and the bundle price should reflect that.
And the bundle should be measured by what it does to the slow product's sell-through, not by the bundle's conversion rate. A bundle that converts well but leaves the slow product in the warehouse, because customers buy it for the bestseller and return the slow item, is not a bundle. It is a discount with extra steps.
The training problem
The risk is not the bundle. It is what the customer learns from it. A customer who buys a bestseller bundled with a slow product at a discount learns that the bestseller is available at a discount, and the next time they want the bestseller, they wait for the bundle. The store has trained them to wait, and the training is permanent, because the customer now knows the discount exists.
The pattern is visible in the data. A store that bundles frequently sees its full-price conversion fall, not because the products got worse, but because the customers got smarter. The discount becomes the price, and the full price becomes the price nobody pays. The bundle that was meant to clear stock has cleared the margin instead.
The fix is to bundle rarely, and to bundle products that the customer would buy together anyway. A bundle that is a genuine combination, the accessory with the product, the refill with the device, does not train the customer to wait, because the customer was going to buy both. A bundle that is a slow product attached to a bestseller trains them, because the customer was only going to buy one.
How to bundle without training discount hunters
Limit the bundle in time. A bundle that runs for two weeks and then disappears is a promotion. A bundle that runs all year is a price. The time limit is what makes the customer buy now instead of waiting, and it is what keeps the full price credible when the bundle ends.
Bundle the slow product with the product it belongs to, not with the bestseller that happens to sell. A slow accessory bundled with its product is a complete purchase. A slow product bundled with an unrelated bestseller is a clearance rack with a bow on it, and the customer can tell the difference.
And measure the return rate on the bundle, not just the sales. Size and fit is the top return reason in apparel, cited by 53 percent of respondents in Coresight Research's survey, and a bundle that pairs a bestseller with a slow product in the wrong size will come back at the rate of the slow product, not the bestseller. A bundle that is returned is worse than a bundle that never sold, because it costs the shipping both ways and the handling.
Related reading on this site: Why does your bestselling product have the worst return rate?, What is bracketing, and why are your best customers your most expensive ones?, and How should a store merchandise a product with 40 variants?.
Frequently asked questions
When does bundling a slow product with a bestseller work?
When the two products solve one problem together, such as an accessory with the product it belongs to, and the bundle price reflects the slow product's clearance value, not its full price. The customer buys the bundle because it is the complete purchase.
Why can bundling train customers to wait for discounts?
Because a customer who buys a bestseller at a bundle discount learns the discount exists, and waits for the next bundle instead of buying at full price. A bundle that runs all year is a price, not a promotion. Limit it in time.
How do I price a bundle with a slow mover?
Price it on the margin, not the revenue. Compare the bundle margin against the margin of selling the bestseller alone, and value the slow product at its clearance value, not its full price. A bundle that raises revenue and loses margin is a loss.
What should I measure after launching a bundle?
The slow product's sell-through, the full-price conversion rate, and the bundle's return rate. A bundle that converts well but leaves the slow product in the warehouse, or that drags down full-price sales, is not working.