A service center in the Midwest processes 800 orders per month. Their average order size is 12,000 pounds and their average margin is $0.03 per pound, so $360 per order. Sounds fine until you calculate what it actually costs to process each order.
The sales rep spends 25 minutes on the order: checking inventory, building the quote, following up, entering the order. At a fully loaded cost of $45 per hour, that is $19 in sales time. The warehouse team spends 40 minutes pulling, staging, loading, and documenting. At $28 per hour fully loaded, that is $19 in warehouse labor. Credit check, invoicing, and collections average $8 per order. Freight coordination adds $6. Quality documentation (MTRs, certs) adds $4.
Total cost to process that order: $56. On a $360-margin order, that is 16% of gross margin consumed by transaction costs. Now look at the orders that are half the average size, 6,000 pounds. Same margin per pound. Same processing cost. You just spent $56 to earn $180. That is 31% of your margin gone before you pay for the building, the inventory carrying cost, or anything else.
Small Orders Are Margin Killers
This is why cost-per-transaction analysis matters. It reveals that not all revenue is created equal. A $500 order and a $5,000 order often require the same number of touches, the same paperwork, the same delivery coordination. The only thing that changes is the material quantity.
We have seen service centers where 30% of their orders generate less than $100 in gross margin after transaction costs. Those orders are not breaking even. They are subsidized by the larger orders. The service center is literally paying to serve those customers.
How to Calculate Your Number
Start with your total operating expenses for a month, excluding material cost and freight. Include salaries, benefits, rent, utilities, insurance, software, depreciation, everything. Divide that by the number of orders you processed that month. That gives you your average cost per transaction.
For a typical service center with $2 million in monthly operating expenses processing 1,200 orders, the cost per transaction is roughly $1,667. If your average order margin is $1,500, you are underwater on the average order before you account for cost of capital on your inventory.
The more refined version segments your costs by function (sales, warehouse, admin, delivery) and assigns them based on actual time spent. This takes more effort but reveals exactly where the cost accumulates.
What to Do With This Information
You are not going to fire your small customers. But you should make informed decisions about how you serve them. Options include setting minimum order quantities or minimum order charges. A $75 small-order surcharge on orders under 5,000 pounds covers your transaction costs and most customers will not even push back.
Another approach is automating the high-touch parts of small orders. If your sales reps spend 25 minutes on every order regardless of size, giving customers a self-service portal for simple reorders can cut that to zero. The order goes straight from the customer to the warehouse pick list.
You can also restructure your sales compensation. If reps earn the same commission percentage on a $500 order as a $50,000 order, they have no incentive to consolidate or grow account sizes. Weight the commission structure to reward larger orders and you will watch average order size climb.
The service centers that track cost per transaction make better decisions about pricing, customer segmentation, process automation, and resource allocation. Everyone else is guessing. And in a business where margins are measured in pennies per pound, guessing is expensive.