How to find your best-selling products (and what to do about them)

"Best seller" sounds simple. In practice there are three different rankings, and a product can be at the top of one and the bottom of another.

• By units: how many you sold. Shows what customers ask for most.
• By revenue: units times selling price. Shows what brings the most money through the till.
• By profit: units times (price minus cost). Shows what actually pays your bills.

Most owners know the units list by feel. The profit list often surprises them.

By units, bread wins with 140. By revenue, bread still leads at $420. By profit, bread ($84) is barely ahead of cola ($81), even though it sold 50 more units. The phone charger sold only 6 but made more profit than 25 bars of soap. Bread brings people in, cola earns almost as much with less work, and the charger is a high-margin item worth keeping in stock and in sight.

The profit column needs cost. Where you do not know the cost, you only have two of the three lists. See gross profit for shop owners.

• Never run out. Give them the highest minimum stock and check them first. See how to make a restock list.
• Give them good shelf space. Eye level and near the till for items that sell on impulse.
• Review their price. If a top seller has a thin margin and few competitors nearby, a small increase may be affordable. If your neighbour sells it cheaper, test carefully. See how to price products.
• Negotiate. Your biggest lines give you the best argument for a better supplier price. See negotiating with suppliers.
• Make them favourites at the till. This speeds up checkout. See how to speed up checkout.

The bottom of the list matters just as much. Products that sell rarely tie up cash and shelf space. Ask for each one: does it bring customers in, does it have a high margin, or does it simply sit there?

• Stop reordering until stock is gone.
• Discount or bundle with a fast seller to clear it.
• Move it to a better spot for a trial month.
• Drop it if it still does not sell.

See slow-moving and dead stock for a full method. Remember seasonal items: a product that is slow in March may be your best in December. Planning for busy season helps.

1. List the top 10 by units

   Check they are well stocked and well placed.

2. List the top 10 by profit

   Compare. Any product on the profit list but not the units list is worth promoting.

3. List the bottom 10

   Decide: stop, discount or drop.

4. Write down one change

   One price, one reorder, one shelf move. Do it this week.

• Short windows. One week can mislead. A funeral, a school event or a power cut can distort the list. Look at a month at least.
• Stock-outs hide demand. If a product sold out on Tuesday, it may have been your best seller if it had stayed in stock. Check that a low-selling product was actually available all period.
• Price changes. If you raised a price and units fell but profit rose, that is good news. Look at profit, not only units, before you reverse a decision.

Also remember that best sellers are about your customers in your location. A product that tops a chain's list may not sell in your street at all. Trust your own records over general advice, including this guide.

Shopkeepa reports show sales by day, week and month, your average sale, best sellers, slow movers, low and out-of-stock items, and inventory value. Where you have entered a cost for a product, it also shows gross profit, so you can see best sellers by profit as well as by units and revenue.

Every sale at the till feeds the reports automatically, so there is no end-of-month typing. Slow movers are listed separately, so decisions about what to stop reordering take minutes. Cashiers cannot see cost or profit, so the margin figures stay private to the owner. Learn more about sales and profit reports. Shopkeepa is in development, and early access shops will help shape it.