Why your best-selling items are not always your most valuable products

Ask any store owner which products are their best, and the answer comes instantly: the ones that sell the most. It’s a natural answer — you see those products cross the counter all day long. But “best seller” and “best product for the business” are two different things, and mixing them up quietly costs money every month.

This article walks through the difference between volume and profitability, how to spot each kind of product in your numbers, and what to do once you know who’s who.

Volume and margin: two different jobs

A high-volume product keeps the store moving: it pulls customers in, fills baskets, and sets the rhythm of the day. A high-margin product feeds the store: every sale leaves a meaningful amount behind once the supplier is paid. Both are useful. The danger is treating them the same way.

High-volume products often carry thin margins precisely because everyone sells them — popular drinks, bread, milk, cigarettes. Customers know those prices by heart, so competition happens at the nickel level. High-margin products tend to be less obvious: house-made items, local goods, accessories, specialty formats.

How to spot each type in your numbers

Pull your sales by item for the past month — your Clover register already records them. For your top 20 or 30 sellers, add your approximate purchase cost. You don’t need accounting precision; the right order of magnitude is enough to rank.

1. Compute revenue per product: selling price × quantity sold.
2. Compute contribution per product: (selling price − purchase cost) × quantity.
3. Rank your products by both columns, side by side.

Products at the top of both rankings are your pillars — protect them. High-volume, low-contribution products are your traffic drivers: they exist to attract, not to enrich. Low-volume, high-contribution products are your hidden gems — they usually deserve more visibility than they get.

What to do with this information

Once your products are sorted by role, several decisions become obvious. Here are four that come up again and again in small retail:

• Give your gems visibility: eye level, near the register, or suggested next to a popular traffic driver.
• Don’t cut the price of an already-thin traffic driver to “sell more” — you’ll raise volume without improving what actually stays in the till.
• Watch supplier cost increases on traffic drivers: a thin margin can quietly turn negative without anyone noticing.
• When a product is strong on both volume and margin, never let it run out. Every day of empty shelf on a pillar is expensive.

“But I don’t know my cost on every product”

That’s true of many stores, and it’s no reason to give up. Start with a family-level approximation: you probably know the usual margin on your drinks, your fresh goods, your tobacco. Apply those family percentages to your top sellers, and refine only where a real decision depends on it. A margin estimated within five points is plenty to separate a traffic driver from a hidden gem — what matters is the ranking, not the decimal.

Over time, fill in real costs for the handful of products where the stakes are highest: your top ten by volume, and any product you’re considering promoting, moving, or dropping. Twenty accurate numbers beat four hundred guesses.

How often should you redo the exercise?

The full ranking with costs is worth redoing a few times a year — at season changes, or whenever a supplier updates their price list. In between, a weekly glance at sales by product is enough to confirm the roles still hold: are my gems still moving? Is a traffic driver slowing down?

Precision isn’t the point — the point is to stop deciding blind. Once you know who attracts and who earns, your pricing, placement, and reorder choices change. And it’s those choices, repeated week after week, that show up at the end of the year.