SKU Fee Structure: How Amazon, Shopify, and Other Marketplaces Cut Your Profits
9 min read
Last month, SKU B07X lost 12% margin. We thought it was just slow sales—until we dug into the SKU fee structure. Turns out, Amazon's $0.30 referral fee plus Shopify's 2% transaction fee was killing us. We weren't tracking these costs per SKU, so the damage was hidden. If you're selling on multiple marketplaces, you're paying different fees for every SKU. Here's how to spot them.
Amazon's SKU Fee Structure: Referral Fees, FBA Fees, and More
Amazon's fee structure is a maze. Referral fees range from 6% to 20% depending on the category. For SKU B07X, we were paying 15%. Then there's FBA fees—$2.41 per unit for standard-size items. Don't forget the $0.30 per item referral fee. That's $2.71 per unit before shipping. If your profit margin percentage is already thin, these fees can wipe it out. We switched fulfillment in March and saved $0.50 per unit.
Shopify's SKU Fee Structure: Transaction Fees and App Costs
Shopify charges a flat 2% transaction fee if you use an external payment gateway. If you're using Shopify Payments, it's 0.5% to 2% depending on your plan. But here's the kicker—apps like GoMarginify add another $9.99 to $29.99 per month. For SKU B07X, the app costs alone added $0.10 per unit. That might not sound like much, but it adds up. We cut two apps and saved $0.05 per unit.
Other Marketplaces: eBay, Walmart, and TikTok Shop Fees
eBay's fee structure is similar to Amazon's, with a 10% final value fee plus a $0.30 per order fee. Walmart takes 15% per sale. TikTok Shop is cheaper at 2% to 5%, but their shipping fees can be a nightmare. We lost $0.20 per unit on TikTok Shop because of hidden shipping costs. Always check the fine print.
How to Calculate Cost Per SKU and Track Profit Margins
The profit margin percentage formula is simple: (Revenue - Cost of Goods Sold - Fees) / Revenue. But tracking it per SKU is the hard part. We used GoMarginify to connect all our marketplaces and see the true net profit per SKU. It showed us that SKU B07X was losing money. We adjusted our pricing and saved 8% margin.
Step by step
- 1
Step 1: List All Fees for Each Marketplace
Start with Amazon's referral fees, FBA fees, and any other costs. For Shopify, note the transaction fees and app costs. For eBay, Walmart, and TikTok Shop, list their fees too. For SKU B07X, we had Amazon's $2.71 fee, Shopify's $0.10 app cost, and eBay's $0.30 fee. That's $3.11 per unit before shipping.
- 2
Step 2: Calculate Cost Per SKU
Take the total cost of goods sold and add all the fees. For SKU B07X, the product cost was $5.00. Adding the $3.11 in fees, the cost per SKU was $8.11. If you're selling it for $10.00, your profit margin percentage is (($10.00 - $8.11) / $10.00) * 100 = 18.9%. That's not great.
- 3
Step 3: Adjust Pricing or Cut Costs
If your profit margin percentage is too low, raise your price or find cheaper fulfillment. We raised the price of SKU B07X to $11.00 and saved 8% margin. If you can't raise prices, cut costs. Switch to a cheaper marketplace or negotiate better rates with suppliers.
- 4
Step 4: Use a Profit Tracking Tool
Tools like GoMarginify connect all your marketplaces and show your true net profit per SKU. They also send daily profit reports via email and IM. We used it to spot losing SKUs and adjust our strategy. It's a game-changer for sellers on multiple platforms.
FAQ
How do I find my SKU fee structure on Amazon?
Go to Seller Central, then Reports > Payments. There you'll see a breakdown of all fees per SKU. For referral fees, check Reports > Business Reports > Individual SKU Performance.
Can I avoid Shopify's transaction fees?
Yes, use Shopify Payments. It's cheaper than external payment gateways. For example, if you're on the Basic Shopify plan, the transaction fee is 2%. With Shopify Payments, it's just 2.9% + $0.30 per transaction.
What's the best way to track profit margins per SKU?
Use a tool like GoMarginify. It connects all your marketplaces and shows your true net profit per SKU. It also sends daily profit reports via email and IM. We used it to spot losing SKUs and adjust our strategy.
How do I reduce my cost per SKU?
Negotiate better rates with suppliers, switch to a cheaper marketplace, or find a cheaper fulfillment method. We switched from FBA to Merchant Fulfilled and saved $0.50 per unit.
Track your real profit across every marketplace
Learn how SKU fees like Amazon's $0.30 referral fee and Shopify's 2% transaction fee eat into your profit margin percentage. Real examples.
Start 7-day free trial