An empty shelf doesn't just cost one sale - it triggers permanent store switching, brand defection, and silent margin erosion that compounds across the supply chain. Learn the five ways out-of-stocks reshape shopper behavior and what supplier leaders must do to reclaim control of the shelf.
On-shelf availability (OSA) is a strategic battlefield in today’s retail reality.
An empty shelf sets off a chain reaction: shoppers may move to a competitor, pick another brand, delay their purchase, or abandon it entirely. Each action silently reshapes revenue, loyalty, and market share for both trading partners (see a very recent example here).
For CPG suppliers, OSA demands ownership. Without a dedicated team accountable for monitoring and improving product availability, losses go unmeasured and opportunities for intervention are missed. OSA can no longer be treated as an afterthought; it requires clear responsibility, structured processes, and a systematic approach to action.
Collaboration with retailer customers is also essential. Suppliers need mechanisms to track OSA jointly, share visibility, and align on definitions of success. Only through partnership can teams act decisively to improve replenishment & retail store execution, prevent revenue leakage, and protect brand share.
Drawing on interviews with supplier sales leaders and merchandising leaders at major retailers, we developed a framework that shows how shoppers respond to out-of-stocks - and how those choices ripple through both supplier and retailer performance.
These findings make one thing clear: accountability, rigorous measurement, and collaboration aren’t optional - they’re essential to preventing lost sales and loyalty.
Imagine a parent heading to their local supermarket for baby formula. The shelf is empty. Frustrated, they drive five minutes to a competitor - and end up doing their entire weekly shop there.
The supplier hasn’t lost the sale; the consumer still bought the brand.
The retailer, however, has lost far more than one transaction - share of wallet, loyalty, and potentially the shopper relationship itself. Research shows that 32% of shoppers encountering an OOS will switch stores, often permanently altering shopping patterns.
For retailers, cross-store switching is the most damaging outcome, as one empty shelf can ripple across multiple categories and visits.
A shopper can’t find their preferred bag of chocolate chip cookies and decides, “I’ll come back next week.”
Neither retailer nor supplier has technically lost the sale yet. But cash flow is disrupted, excess inventory sits idle elsewhere, and the supplier’s demand signal is distorted.
This uncertainty drives the bullwhip effect: exaggerated swings in orders and replenishment occur because the system cannot distinguish a delayed sale from a lost one.
Studies show that delayed purchase behavior can inflate forecasting errors by up to 20%, creating unnecessary costs across the customer supply chain.
Sometimes, consumers stay loyal, grabbing a six-pack instead of the twelve-pack they originally intended to purchase.
Good news: the supplier retains the shopper.
Bad news: revenue and margin may still be lost if the substitute item is smaller, cheaper, or less profitable.
Nearly 25% of substitutions result in a lower-margin sale. On paper, in-stocks look healthy, but the P&L quietly erodes - a hidden cost of OOS that compounds over time.
A shopper looking for their preferred shampoo finds it missing and grabs a competitor’s product instead.
The retailer preserves the basket; the supplier suffers a direct hit - and possibly a long-term one.
Up to 37% of consumers never return to their original brand after switching due to an OOS. Even a single empty shelf can trigger lasting brand defection, eroding loyalty and market share while competitors capitalize on the opportunity.
Finally, the simplest yet most damaging scenario: the consumer walks away.
The item isn’t bought. The basket is smaller. Both retailer and supplier absorb the hit.
Out-of-stocks aren’t just a matter of success or failure - they set off a chain of outcomes, with winners and losers at every step. Yet too many retailers and suppliers are still navigating in the dark when it comes to measuring and improving OSA.
For supplier leaders who want to change this reality, the path forward is clear:
In today’s competitive retail landscape, the shelf is the ultimate test of a brand’s relevance and resilience.
Suppliers who treat OSA as a strategic lever - with clear ownership, measurable goals, and strong collaboration with retail partners - don’t just prevent losses.
They actively shape shopper behavior, protect loyalty, and secure long-term market leadership.
