Why margin leakage keeps happening in ecommerce.

By this point, most brands understand where margin tends to slip.

It shows up in retail deductions, fulfillment discrepancies, and shipping costs. And once you start looking, it’s usually easy to find examples.

The harder question is: why does it keep happening?

Because in most cases, they’re a natural result of how ecommerce systems operate at scale.

In a recent webinar with Intentwise, I talked about this idea in more detail — that margin leakage isn’t usually caused by a single failure. It builds over time as automated systems process large volumes of transactions.

It’s not one system. It’s many.

One of the biggest challenges in ecommerce operations is that margin leakage doesn’t come from a single place.

It shows up within whichever systems you rely on, whether that’s retailers, marketplaces, or carriers.

• When you sell to retailers as a vendor, they manage receiving and deductions.
• When you sell through marketplaces, they manage inventory and fulfillment.
• When you ship direct to customers, carriers control your contracts and billing.

Each of these systems operates independently, with its own data, processes, and priorities.

Most of the time, they work well within their own environment.

But at scale, each of them produces small discrepancies. A deduction applied incorrectly; inventory recorded inaccurately; a charge that doesn’t quite align with the contract.

Individually, those issues are minor. But because they happen continuously, they become a consistent source of margin leakage.

Retail systems are designed to enforce compliance.

In retail and wholesale, deductions and chargebacks aren’t exceptions. They’re part of how the system works.

Retailers use them to enforce standards across their supply chain:

• delivery windows
• packaging requirements
• labeling accuracy
• data transmission

At scale, these processes rely heavily on automation.

That means deductions are applied based on system rules. Sometimes, those rules produce outcomes that don’t fully reflect what actually happened. For example, a deduction might be applied to the wrong shipment, duplicated, or based on misinterpreted receiving data.

From the retailer’s perspective, the system is working as designed.

From the vendor’s perspective, there’s a discrepancy.

And unless someone checks the data closely, that gap remains, and you lose money.

Fulfillment networks are built for speed, not perfect traceability.

Marketplace fulfillment systems are designed to move inventory quickly and efficiently.

That means:

• inventory passes through multiple facilities
• items are received, transferred, and stored across locations
• systems track movement in near real-time

At this scale, the focus is on speed. Small discrepancies are inevitable in how inventory movements are recorded.

For example, inventory moving between facilities may be recorded as partially received, even when it hasn’t actually left the network.

Nothing “broke” in the system. The data simply didn’t fully reflect what happened in that specific movement.

Individually, these discrepancies are often small. But they occur continuously across large volumes of inventory.

And over time, that creates a measurable impact.

Carrier systems are optimized for their margins, not yours.

Shipping introduces a different kind of system behavior.

Carriers operate on complex, structured pricing models:

• base rates
• accessorial fees
• fuel surcharges
• service guarantees

These are defined through contracts that account for tens of thousands of combinations. Fully understanding every variable is impossible.

Importantly, carrier incentives aren’t aligned with yours. As I mentioned in the webinar:

“Carrier reps are measured on delivering profitable accounts to the carrier, not on saving you the most money.”

That doesn’t mean anything is being done incorrectly. It just reflects how the system is designed to operate.

At scale, small inefficiencies in the contracted variables can become very expensive.

Why these issues persist.

Across all of these systems, there’s a consistent pattern: you’re relying on system-reported data, and small discrepancies aren’t actively corrected.

Once products leave your warehouse:

• retailers report what they received
• marketplaces report how inventory moved
• carriers report how shipments were billed

Each system assumes it’s correct. And any errors are often too small for you to immediately notice.

But at scale, they compound quickly.

And because these systems are designed to operate efficiently — not to validate outcomes — those discrepancies aren’t automatically corrected.

They persist.

What this means in practice.

Once you understand that these discrepancies are systemic, the approach changes.

It’s no longer enough to:

• spot occasional issues
• react to individual discrepancies

Instead, you need to treat this as an operational process.

In practice, that means:

• regularly reviewing system-reported data, not just financial summaries
• comparing what should have happened with what was recorded
• identifying patterns, not just one-off issues
• building a consistent process to investigate and resolve discrepancies

For most teams, doing that manually is difficult to sustain. That’s why many brands are starting to use tools like Margin Pro to automate reconciliation, identify discrepancies at scale, and manage recovery as an ongoing process.

Because if the system produces these issues continuously, your response has to be continuous as well.

Final thoughts.

Revenue leakage in ecommerce isn’t usually caused by one mistake.

It’s the result of systems operating at scale, each producing small discrepancies over time.

Individually, those issues seem insignificant. But they don’t resolve on their own.

They’re not exceptions. They’re part of how the system works.

And once you understand that, the implication is clear: this isn’t something you fix occasionally. It’s something you need to manage continuously.