A customer lands on your site, adds items to their cart, and at checkout they open a new browser tab and search "[your brand name] promo code." Within seconds they're on RetailMeNot or a similar coupon aggregator, pasting a code they found there. The sale goes through. You pay a discount you never planned. If you run an affiliate program, you may also pay a commission to the site that "referred" that customer, even though that customer was already in your checkout.
This is not a rare edge case. According to Shopify's research on checkout behaviour, a significant share of cart abandonments happen at the moment shoppers see the promo code field and go looking for a discount they don't have. Some come back with one. You pay for it either way.
1. You have active codes you forgot you created
This one is embarrassingly common. A code gets created for a trade show two years ago, or for a podcast sponsorship that ran once. Nobody deactivates it. Coupon sites scrape or crowd-source these codes and publish them indefinitely. Your customers find them. You keep honouring them.
The fix is simple: export every active discount code from your platform right now and delete anything without a clear expiry date or a specific ongoing purpose. If you can't explain why a code exists, it shouldn't be live.
2. Your affiliate program pays for sales you already had
Affiliate programs are supposed to bring you customers who wouldn't have found you otherwise. Coupon aggregator sites exploit a loophole: they get the affiliate cookie dropped at the last second, right when your customer pastes their code at checkout. The customer was already buying. You pay the commission anyway.
The BDC notes that affiliate marketing can be a cost-effective channel for Canadian SMBs, but only when the program is structured to reward genuine referrals, not last-click coupon plays. If you run an affiliate program, audit which partners are sending you real traffic versus which ones are just capturing the commission at the finish line.
3. The promo code field itself signals "go find a discount"
The moment a customer sees an empty promo code field, many of them assume they're missing something. It's a psychological trigger. They leave your checkout to search for a code. Some don't come back. Of those who do, a portion return with a code from a site you're indirectly funding.
You don't have to remove the field entirely. Some platforms let you hide it behind a link that only expands when clicked. That small change reduces the impulse to go searching. It's not a trick; it's just not dangling a question mark in front of people who were ready to pay full price.
4. You're stacking discounts without realising it
Here's a scenario that plays out more often than it should. A customer uses a 15% affiliate coupon code. Your platform also has a free shipping threshold set at $75, which they hit. You've now given up 15% margin plus the shipping cost on an order you would have fulfilled at full price. If your average order value is around $90 and your product margin is 40%, you may be net-negative on that transaction after fulfilment costs.
Map out your discount stacking rules. Most e-commerce platforms allow you to set codes as non-combinable. If yours doesn't, that's a platform configuration issue worth fixing before you run your next promotion.
5. You've never actually measured what your discount codes cost you
This is the root problem. Most Canadian SMB owners know roughly what they spend on ads. Almost none of them have ever sat down and calculated the total cost of their discount ecosystem: every active code, its redemption rate over the last 12 months, the revenue it touched, and the margin impact. When we do this as part of a growth & operations audit, the number is almost always a surprise. Not always a bad one, sometimes a code is genuinely driving incremental revenue. But often, 60-70% of discount redemptions are on orders that would have happened anyway.
The audit itself takes less than an hour if your data is clean. You need: a list of all active codes, total redemptions per code, average order value with and without a code, and your affiliate commission log if you run a program. That's it. From there, you can make an informed decision about which codes to keep, which to kill, and what a promo code field that actually serves your margin looks like.
FAQ
How do I know if affiliate coupon sites are costing me money?
Pull your affiliate or discount code report for the last 90 days. If you see codes you didn't create or distribute, someone else did, and you're paying for it. Cross-reference with your analytics to see which sessions include a coupon search just before checkout.
Should I remove the promo code field from my checkout?
Not necessarily. The field itself isn't the problem. Removing it can frustrate customers who have a legitimate code. The fix is to audit which codes are active, who issued them, and whether those discounts are actually driving new customers or just rewarding people who would have bought anyway.
How do I get a promo code for my own store?
You create them inside your e-commerce platform (Shopify, WooCommerce, etc.). The more useful question is how to track exactly who uses them and whether each code is generating margin-positive revenue, not just volume.
What is a typical affiliate commission rate in Canada?
It varies by category. Most Canadian SMB affiliate programs pay between 5% and 15% of the sale value. When you add a coupon discount on top of that commission, you can easily be giving away 20-25% of the order value on a sale you would have made regardless.
If you want to run this audit properly and connect it to a broader picture of where your margin is actually going, our strategy services start exactly there: the diagnosis, the numbers, then the decisions.
