How to Analyze Your Best-Selling Products to Drive More Profit

Photo by Woliul Hasan on Unsplash 

If you're like many eCommerce sellers, you can probably list your best-selling products off the top of your head. But do you know which products are actually driving your profit—not just your sales? 

As an accountant who works closely with online sellers, I’ve seen too many entrepreneurs fall into the trap of focusing on revenue without understanding the bottom-line impact. A product that sells a lot but eats up your margins may be dragging your business down more than you realize. 

Here’s how to dig into your numbers so you can focus on what’s truly profitable—and grow your business the smart way. 

 1. Start with Your Top-Selling Products 

Pull a report from your sales platform (Amazon, Shopify, etc.) showing total units sold and total revenue for each product over a specific time period—monthly, quarterly, or annually. 

Then sort your products by: 

• Total revenue 

• Units sold 

• Average selling price 

This gives you a clear picture of what’s moving—and how much money it’s bringing in. 

 2. Layer in Product-Level Costs 

Revenue is only half the story. Next, figure out what each product costs you to sell. This includes: 

• Cost of goods sold (COGS): What you pay your supplier or manufacturer 

• Shipping and fulfillment: Amazon FBA fees, 3PL costs, packaging 

• Marketing: Sponsored ads, influencer commissions, or any direct ad spend tied to that product 

• Returns and refunds: Some products have higher return rates that chip away at profitability 

• Platform fees: Amazon, Shopify, or marketplace commissions 

If you’re not tracking these costs by SKU, now is a great time to start. Your accounting software and inventory tools can often help here—or you can work with your accountant (like me!) to build this out. 

 3. Calculate Profit per Product 

Now subtract all those costs from your product revenue to get your net profit per product. You can look at: 

• Gross profit = Revenue – COGS 

• Net profit = Revenue – (COGS + fulfillment + ads + returns + fees) 

Create a chart or spreadsheet that shows each product’s total revenue and total profit. Some of your best-sellers might not be your best earners once you factor in all the costs. 

 4. Identify Your High-Margin Winners 

Look for products that meet two criteria: 

• Sell well (decent volume or revenue) 

• Have healthy margins (above your average profit per unit) 

These are your profit drivers—the products that should get more of your attention, ad spend, and inventory investment. 

Likewise, flag your low-margin best-sellers. These are tricky. They might be: 

• Worth keeping because they bring in new customers or help you rank better 

• Worth improving (e.g., negotiate a better COGS or raise the price) 

• Or worth dropping if they’re draining your resources 

5. Double Down on What Works 

Once you know your winners, consider: 

• Increasing ad spend for those products 

• Bundling them with lower-performing items to boost overall cart value 

• Featuring them more prominently on your website or listings 

• Planning inventory around peak performance seasons for those products 

At the same time, don't be afraid to cut or revamp low-profit items—even if they’re top sellers. Your energy should go where the profit is. 

 Final Thoughts 

Analyzing your best-sellers isn’t just a feel-good exercise—it’s a core part of running a more profitable eCommerce business. If you’re not already tracking product-level profitability, now’s the time to start. You don’t need to do it all overnight, but the more clarity you have, the better decisions you can make. 

If you'd like help setting this up, reach out. I help online sellers make sense of their numbers every day—and I’d love to help you grow a more profitable, sustainable business.