Shopify Product Sales: Grow Beyond One Bestseller

When one item dominates your Shopify product sales, the tempting response is to push everything else harder. First ask whether customers have been given a convincing reason to buy the rest of the range at all.

A bestseller can be a healthy entry point into the business. The problem is concentration without understanding: you do not know whether other products lack exposure, solve a different need or simply belong later in the buying journey. Diagnose those possibilities before adding discounts, recommendation apps or a larger advertising budget.

By David Black, founder of PureRapid. Editorial analysis; sources checked 21 October 2026.

Low sales do not prove low demand

If most advertising lands on the hero product, it should receive more opportunities to sell. Comparing unit sales alone treats that unequal exposure as a fair test of customer preference.

For each important product, examine relevant product-page visits, availability, add-to-cart behaviour, completed orders, returns and contribution. Check whether a product is visible in the right sales channel and available to the shopper’s market. A hidden or unavailable variant has not failed a demand test.

Separate new visitors from existing customers where the data allows it. Someone arriving for a specific product may have no reason to browse the full catalogue. A returning customer may need a refill, a compatible accessory or a different format.

Do not expect every SKU to become an acquisition hero. Some earn their place through repeat purchases or a profitable addition to an existing order. Others tie up stock and attention without making the customer proposition stronger.

Give every supporting product a commercial job

Place each product into one of three roles. A companion helps the buyer use or complete the main purchase. A continuation serves a later need. A separate proposition appeals to a different problem, occasion or audience.

A compatible attachment may belong beside the hero product. A consumable refill may belong in a later replenishment journey. A premium alternative may replace the first choice rather than add to it. Treating all three as “you may also like” hides those differences.

Write one sentence explaining the connection from the customer’s perspective. If the best reason is “we have a lot of these in stock”, the merchandising problem begins before the website layout.

A worked range: one bestseller, three different next steps

Illustrative example, not a PureRapid client result. Imagine a coffee retailer whose filter-brewing starter kit dominates first orders. It also sells paper filters, replacement coffee and commercial espresso machines. Putting all three into the same recommendation carousel asks the buyer to solve three unrelated decisions.

The paper filters are a candidate add-on, not a compulsory bundle. If the kit already provides enough for the customer’s immediate need, the addition may belong later. Compatibility and timing make the recommendation useful; excess stock does not.

For each candidate, record its buying job, eligible audience, current exposure, contribution after costs and the next behaviour you expect. That gives the team a testable brief before anyone changes the theme.

Diagnose Shopify product sales before changing the range

These patterns are clues, not causal proof. A product page can receive the wrong traffic, and a small sample can move sharply after only a few orders. Check the customer journey directly before declaring a winner or loser.

For a wider journey problem, use our Shopify conversion diagnosis. Keep the question here narrower: what prevents the right customer from understanding and choosing this particular product?

Make one recommendation worth noticing

Start with a genuine relationship between products. Explain what the addition does, whether it is compatible and why somebody would want it now. A small, relevant recommendation can be more useful than a large carousel of weakly connected stock.

Shopify Search & Discovery supports customising related and complementary recommendations. Display depends on the theme having the relevant sections and on product eligibility. Check the live theme and product settings before assuming another paid app is necessary.

Before adding a new app, price its subscription, theme impact and maintenance against the expected contribution. A recommendation that adds sales but absorbs the gain in operating costs has not improved the commercial result.

Test the actual mobile experience. The recommendation should not interrupt the main product’s price, options or purchase action. Confirm that selecting an add-on produces the intended item and variant, with no confusing default selection.

Keep a later purchase for the later moment. Use observed replenishment timing or a genuine next step, rather than immediately promoting a replacement for something the customer has just bought. Use only permitted customer communications.

Check the live recommendation, not only the app setting

In Shopify Search & Discovery, choose the hero product and add a relevant complementary product. Confirm the theme displays the complementary-products section. Then visit the product page in a clean session and check the actual market, variant, price and stock.

Shopify’s current requirements include an active product published to the Online Store. A complementary recommendation must have inventory above zero. Related-product availability has different rules, so do not assume both placements behave alike. A saved configuration is not proof that a customer sees it.

Measure contribution per eligible visitor

A higher average order value can conceal fewer orders. Evaluate the recommendation across everyone eligible to see it, including visitors who leave without buying.

Illustrative example, not a PureRapid client result. Imagine a test with 10,000 comparable eligible visitors in each group. The original journey converts 300 hero orders. Each leaves £24 after product cost, discounts, fulfilment, payment fees and an allowance for refunds. Total contribution before acquisition and fixed overhead is £7,200.

The recommendation journey produces 290 hero orders and 70 add-ons. Hero contribution is £6,960. If each add-on contributes £7 after its additional costs, it adds £490. Total contribution is £7,450, or £0.745 per visitor, against £0.72 in the original group.

The observed difference is £250, about 3.5%. That is a calculation, not proof of a reliable uplift. The experiment still needs an appropriate design, enough evidence and allowance for returns and uncertainty. Assume comparable visitor acquisition cost and no test-specific software or setup cost; subtract any difference before deciding.

Find the point where the recommendation stops helping

Holding the 70 add-ons constant, 280 hero orders would leave £6,720 + £490 = £7,210. At 279 hero orders, the result falls to £7,186, below the original £7,200. The add-on revenue cannot justify unlimited damage to the main purchase.

All figures are GBP for the stated test groups, excluding recoverable VAT. They are illustrative assumptions, not conversion benchmarks. A real test must allow for different shipping thresholds, returns, stock costs and the time it takes to collect the result.

Write the test rule before you read the result

Keep visitor eligibility and measurement consistent. Record hero orders, add-on units, net sales, variable costs and the contribution per eligible visitor for each group. Set a tolerable fall in hero conversion and a review point that gives returns time to appear.

Use a randomised comparison where your setup and volume support it. A before-and-after change during a promotion or stock shortage cannot isolate the recommendation’s effect. If evidence is thin, keep the change small and record the uncertainty instead of declaring an uplift.

Check the margin consequences of discounts and fulfilment before using a larger basket as the success measure.

Check whether the hero brings the right next customer

Group customers by their first product and follow subsequent orders over equal periods. Compare the share who return, what they buy next and the contribution they leave after retention costs. Do not compare a year-old group with customers acquired last week.

Shopify’s customer reports include cohort analysis, but the definitions and selected metrics matter. Revenue or projected spend is not automatically contribution. Reconcile the analysis with product costs and actual refunds.

A hero product that attracts one-time bargain buyers may need a different offer or acquisition strategy. A hero that leads to profitable repeat purchases may deserve continued focus even if the rest of the catalogue sells less frequently.

Decide what the range should become

1. Audit exposure and availability. Establish whether each important product has had a credible chance to sell.
2. Assign a role. Identify one companion, one later purchase and any product that needs a separate proposition.
3. Run a bounded merchandising test. Measure contribution per eligible visitor and protect the main purchase.
4. Review stock after the evidence. Improve, reposition or reduce the range based on demand and economics, not a desire for equal sales.

A concentrated business may be making a sensible choice. Diversification becomes useful when it creates another credible source of customer value and contribution, rather than a longer catalogue to maintain.