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Ecommerce Margin Optimization: How We Cut Costs by

Updated 9/25/2026

10 min read

Last month, a SKU lost margin. We thought we were pricing competitively, but hidden fees and ad spend ate into profits. That’s when we realized ecommerce margin optimization isn’t just about markup—it’s about controlling every cost. Here’s how we turned it around.

Why Ecommerce Profit Margin Isn’t Just About Price

We used to think raising the a SKU price would fix margins. Wrong. A $3.20 referral fee on Amazon and a ad spend on TikTok Shop meant we were losing $5.70 per unit. Margin selling is about more than markup—it’s about tracking every cost. Profit margin synonyms like ‘net profit’ or ‘bottom line’ don’t capture the complexity. You need to see the full picture.

How to Calculate True Profit Margin per Unit

True profit margin isn’t revenue minus product cost. It’s revenue minus product cost, platform fees, shipping, ad spend, and refunds. For example, selling a $20 item with a $5 product cost, $3.20 referral fee, $2 shipping, and $3 ad spend leaves you with $6.80 profit. That’s a margin, not the you might assume. Tools like GoMarginify automate this, but you can start with a spreadsheet.

How We Diagnosed Losing SKUs and Fixed Margins

We switched fulfillment in March and saw a drop in shipping costs. But a SKU still bled money. Turns out, high refund rates and missing costs hid the real issue. We cut ad spend by and raised the price by $2.50. Margin jumped from to. The lesson? Diagnose before you act.

Step by step

  1. 1

    Step 1: Track Every Cost

    List every fee—platform, shipping, ads, refunds. For a SKU, we missed a $1.50 refund fee per unit. That’s $1,500 lost on 1,000 units. Use a tool like GoMarginify to automate this.

  2. 2

    Step 2: Adjust Pricing Based on True Margin

    If your true margin is but you need, raise the price or cut costs. We raised a SKU by $2.50 and saw no drop in sales. Sometimes, buyers don’t notice small price hikes.

  3. 3

    Step 3: Cut Unnecessary Ad Spend

    We spent $3 per unit on TikTok Shop ads. After reducing spend by, sales dropped only. That’s an extra $1.50 profit per unit with minimal sales impact.

  4. 4

    Step 4: Negotiate Better Shipping Rates

    We switched fulfillment in March and saved on shipping. If you’re shipping 1,000 units monthly, that’s $2,000 saved. Reach out to suppliers for bulk discounts.

FAQ

How do I calculate profit margin per unit?

Subtract product cost, platform fees, shipping, ad spend, and refunds from revenue. For example, a $20 sale with $5 product cost, $3.20 referral fee, $2 shipping, $3 ad spend, and $1.50 refunds leaves $6.80 profit. That’s a margin.

What’s the difference between markup and margin?

Markup is the percentage added to product cost to get the selling price. Margin is the percentage of revenue left as profit after all costs. A markup doesn’t mean margin.

How do I find losing SKUs?

Track profit per SKU. Tools like GoMarginify flag low-margin or high-refund SKUs. We found a SKU was losing money because of high refunds and ad spend.

Should I raise prices to improve margins?

Only if your true margin is too low. We raised a SKU by $2.50 and saw no sales drop. Test small increases first.

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