You pack an order, reach for the third item, and the shelf is bare. Now you either ship it short, swap in something else, or cancel and refund. Recent research shows how much that costs in repeat business, and what a small online seller can do about it before it happens.

What goes wrong with online orders in omnichannel retail?

Customers increasingly receive online orders with missing or substituted items, according to a July 2025 Harvard Business Review article by Pedro Amorim, Fredrik Eng-Larsson and Robert Rooderkerk. Omnichannel retailers promise a full order, and too often deliver a partial one.

Omnichannel simply means selling through more than one door, such as a shop, a website and a marketplace. The more doors you have, the more places the same stock can be promised, which is why the gaps show up there first. The HBR page we reviewed is a summary and doesn’t report a sample size or method, so treat the findings as direction, not a measured rate.

Do fulfilment failures cost repeat sales?

Yes. HBR says fulfilment failures make customers wait longer before buying again and spend less when they return. The cost of a bad order lasts beyond the refund (Harvard Business Review, 2025).

For a small shop, repeat buyers are usually the most profitable ones. A missed order doesn’t only lose one sale; it can slow down every sale that customer would have made next.

Fulfilment failures make customers wait longer before buying again and spend less when they return (Harvard Business Review, 2025).

Which annoys shoppers more, substitutions or missing items?

HBR says substitutions often frustrate shoppers more than missing items do. Sending a different product feels like a decision made for the customer, whereas a clear shortage at least lets them choose.

Here’s the practical way to think about it. Substituting isn’t automatically kind. Unless the customer agreed in advance, a quick message offering a refund or a wait is safer than quietly swapping in something you think is close.

How do big retailers reduce the risk?

They use stores as fulfilment points: Walmart fulfils about half of its online orders (roughly 50%) through stores, and Target fulfils 95% through nearly 2,000 locations (Harvard Business Review, 2025). HBR notes Target made a US$3 billion investment to get there.

That only works when the system knows what’s on each shelf. A small seller doesn’t need a US$3 billion budget, but the principle carries over: the order can only be promised if the stock behind it is real and visible.

What do the authors recommend?

Prevent stock-outs, and rethink when and how substitutions are used. In other words, fix the cause first and treat substitution as a fallback, not a plan.

The same logic applies at any size. Most missing-item problems start earlier than packing: the website showed stock that had already gone.

How often are small sellers blind to stock-outs?

Nearly 1 in 4 small retailers only learn an item is out of stock when a customer tries to buy it, according to the Global Payments 2025 Retail Inventory Report of 200 small retailers. For those shops, the first alarm is an unhappy customer.

The survey is small, so read it as a pointer. It still matches what many owners already know from experience: the count in the system and the count on the shelf drift apart.

Nearly 1 in 4 small retailers only learn an item is out of stock when a customer tries to buy it (Global Payments, 2025).

How much repeat business is at stake?

16% of small retailers say up to half of their customers never return after a shortage, according to Global Payments (2025). That figure is the share of retailers reporting it, not the share of customers lost across the board.

Even so, it shows why a missing item is more than a refund. If one in six shops can lose up to half its customers to shortages, preventing them is worth real effort.

How do I stop WooCommerce selling stock that’s in someone’s unpaid cart?

Use WooCommerce’s Hold Stock (minutes) setting, which reserves stock for ‘Pending payment’ orders and releases it when the time runs out. Hold Stock is set in minutes, applies only to ‘Pending payment’ orders, and is switched off when left blank (WooCommerce documentation, 2026).

You’ll find it under WooCommerce, Settings, Products, Inventory. Turn on Manage stock and a Low Stock Threshold at the same time, so you’re warned before the shelf is empty rather than after.

Walmart fulfils about half of its online orders through stores and Target fulfils 95%, which only works when shelf stock is visible online (Harvard Business Review, 2025).

Will stores stay important as online grows?

Yes. Forrester forecasts US e-commerce at US$1.8 trillion, or 29% of retail sales, by 2030, which leaves most sales in stores. That’s a US forecast, but it shows why online and in-store stock need to be one picture.

If a customer can buy from your shop and your site, a sale in one place has to lower the count in the other straight away. Otherwise you’ll keep promising items twice.

What drives the cost behind all this?

Out-of-stocks account for 65.6% of the roughly US$1.7 trillion lost to inventory distortion each year, according to IHL Group figures reported by Retail Insight Network (2026). Overstocks make up the remaining 34.4%.

So the biggest lever is simply not selling what you don’t have. A tool that connects your store and marketplace listings to one central stock count helps with that; Asalta eCommerce does this, linking an online store and marketplace listings to central stock, and it’s one option to look at alongside others. You can read more on the Asalta eCommerce page.

Key Takeaways

• Short orders cost repeat sales: fulfilment failures make customers wait longer to buy again and spend less.
• Substitution isn’t a safe fix: shoppers are often more frustrated by swaps than by missing items.
• Fix the cause: 65.6% of inventory distortion comes from out-of-stocks.
• Use Hold Stock in WooCommerce: set it in minutes so unpaid carts don’t block real buyers.