How Bundles Improve Retention (And Keep Your Profits From Evaporating)

Customer retention is one of the biggest challenges in ecommerce. Discounts and promotions may drive a surge of new customers, but once the initial rush is over, how do brands keep them engaged and profits sustainable?

One of the most effective ways to strengthen retention is through product bundling. Thoughtful bundling strategies not only increase average order value (AOV), they also encourage repeat purchases, build loyalty, and improve overall customer satisfaction.

This article explores:

Why retention starts with unit economics
How product bundles improve retention at every stage of the customer journey
How to decide what to bundle
The types of product bundling retailers can use
The operational challenges that can derail bundling strategies
How Simple Bundles helps 20,000+ merchants scale bundles without chaos

Why Retention Starts With Unit Economics

Sustainable customer retention begins with healthy unit economics. While AOV shows cart size and ROAS shows revenue per ad dollar, profit per session is the metric that connects the full picture—combining profit margins, traffic quality, and conversion rate.

For example:

If AOV is $60
And the profit margin is 50%
Each order generates $30 in profit

The goal is to steadily optimize and grow profit per session. Product bundling supports this by increasing order values without letting costs like shipping, pick/pack, or inventory management scale at the same rate. In other words, bundles create more profitability from each interaction while protecting margins.

Why Bundles Improve Retention

Bundles provide both perceived value and convenience, creating reasons for customers to keep coming back.

They:

Increase AOV by packaging complementary products into a bundle offer
Boost sales by introducing new products alongside popular products
Encourage repeat purchases when customers discover a different product they may not have tried otherwise
Deliver greater value through creative formats like mix-and-match bundles, subscription bundles, or even gift bundles with a discounted price

By tailoring bundles to customer segments and customers’ needs, retailers can improve user experience while strengthening long-term loyalty.

Pre-Purchase vs. Post-Purchase Bundles

Bundling opportunities exist at multiple touchpoints in the customer journey.

Pre-Purchase Bundles

Presented before checkout—on product pages, collection pages, or in the cart.

These bundles:

Increase sales by encouraging larger carts
Guide shoppers toward the right products with curated sets
Simplify the decision-making process and improve customer experience

Post-Purchase Bundles

Offered after the initial order—on the thank-you page, in follow-up emails, or months later.

These bundles:

Capture incremental revenue with no additional acquisition cost
Create upsell opportunities that improve revenue streams
Encourage repeat purchases with complete product combinations

For example, a shopper who buys a single product like a skincare serum can later be offered a full routine bundle at a lower price through a replenishment campaign.

The timing of these offers is critical—bundles should feel helpful, not intrusive.

How do you know what to bundle?

Knowing what to bundle is often the hardest part. Data and customer insights provide clear answers:

Cart analysis Use tools like Shopify’s cart analysis to identify products frequently purchased together. If items are paired 25% of the time or more, that’s a strong case for bundling.
Purchase sequence Look at what customers buy first and then what they return for within 30–60 days. For example, one footwear brand found shoppers buying neutral-colored shoes twice within two months. A “Neutral Essentials” bundle with the two most popular colors solved that need.
Seasonal trends Seasonal bundles align with customer needs throughout the year, such as holiday gift sets or a dry skin kit in winter.
Social listening Monitor surveys, reviews, and even TikTok routines to see how customers pair products. If shoppers are combining a brand’s lip liner with a competitor’s gloss, that signals an opportunity to bundle in-house products instead.

Popular Bundle Types

Merchants across industries find success with a variety of bundle types:

Curated kits and sets
Mix-and-match bundles with personalized options
Tiered bundles that reward buying more
BOGO (buy one, get one) or BXGY promotions
Free Gift With Purchase — a new option recently added to Simple Bundles

Each of these formats gives customers a reason to spend more while delivering value beyond standard discounts.

When Bundling Breaks: The Operational Pitfalls

A great bundle isn’t just about what your customer sees on the product page—it’s also about what happens behind the scenes.

The most common issues we see with bundling include:

Inventory mismanagement (overselling or understocking bundles)
Fulfillment errors (wrong sizes, missing items, incorrect substitutions)
Workflow chaos (when systems and warehouses can’t process bundles correctly)

These problems are exactly why some merchants shy away from bundling. If your backend can’t support bundles, your retention strategy quickly turns into a support nightmare.

Making Product Bundles Work at Scale

This is where technology makes the difference. Tools like Simple Bundles remove the operational roadblocks so merchants can focus on the strategy, not the headaches. Key features include:

Automatic inventory syncing: bundles break into individual SKUs at checkout, keeping stock levels accurate.
Seamless integrations: bundles flow through Shopify POS, ERPs, WMS, and 3PLs without manual workarounds.
Clean fulfillment processes: warehouses receive itemized pick lists, reducing errors and speeding up delivery.
Actionable analytics: track which bundles perform best, which components are most popular, and which logic delivers the highest profit per session.
No variant limits: bypass Shopify’s restrictions with an Infinite Options bundle type that allows trillions of possible combinations.

With the right systems in place, product bundles shift from being an operational risk to a scalable retention strategy that builds long-term loyalty.

Key Takeaways

Retention is built on strong unit economics, and product bundles are one of the most effective ways to improve them. By increasing order value, encouraging repeat purchases, and reducing returns, bundles strengthen the relationship between customers and brands.

More than 20,000 merchants already use Simple Bundles to build profitable bundles that keep customers coming back.

A free plan is available for up to three bundles, with all bundle types included.