Bundles are a proven e-commerce tool when used correctly. Done poorly, they can backfire: they confuse customers, erode margins and signal price pressure.
The question isn't whether to bundle, but when and how.
What the research says
A classic study on bundling comes from Stremersch & Tellis (2002). They distinguish between price bundling, offering two products together at a lower price, and product bundling, where the combination itself creates additional value.
Product bundling is stronger in the long term because it creates value rather than simply reducing the price.
The four types of bundles, and when they work
Only available together
Works for complementary products that depend heavily on each other. Example: software + license. Risky when customers may want only one component.
Available individually or as a bundle
Highest conversion and AOV. Customers retain the choice, while the bundle offers a visible discount or additional value. The best option for most e-commerce stores.
Complementary products
"Frequently bought together." The Amazon effect. Works best when the combination makes intuitive sense, camera + memory card, for example, rather than feeling forced.
Starter / Pro / Premium
Particularly effective for digital products, subscriptions and service packages. The decoy effect can make the preferred option more attractive, often steering customers toward the middle tier.
When does a bundle make sense? Practical decision rules
A bundle makes sense when …
The products are complementary. They genuinely work better together. The customer value created by the combination is higher than the value of the individual products on their own.
The margins support it. A bundle discount, ideally 15–25%, reduces contribution margin, but the higher order value can offset that. Run the numbers.
One product has strong pull. A bestseller can bring weaker products along with it, increasing their visibility without requiring a separate campaign.
The customer wants fewer decisions to make. Bundles reduce cognitive load. "Everything I need" is a powerful reason to buy.
the products don't naturally belong together · the discount destroys the margin · customers perceive the bundle as a rip-off because the products are too unrelated · the individual products cost less than the bundle, creating a pricing inconsistency · one product is perceived as inferior and lowers the perceived value of the entire bundle.
The psychology behind bundle decisions
- Loss aversion: "If I don't choose the bundle, I'm leaving money on the table." The perceived loss of the savings can feel more significant than the additional spend.
- Mental accounting (Thaler): customers evaluate bundles differently. A CHF 79 bundle is perceived differently from the same two products priced at CHF 49 + CHF 39, even when the savings are identical.
- Decoy effect: a strategically weaker option can make another option appear more attractive. Tiered bundles use this effect systematically.
- Endowment effect: once the bundle is in the cart, it begins to feel like it belongs to the customer. Removing it can feel like giving something up.
"Bundles aren't a discount tool. They're a value tool. The difference lies in the positioning." — Stremersch & Tellis, Journal of Marketing, 2002