Discount codes leaking to coupon sites: how to stop it and what to do when it happens

.comparison-cards { display: flex; flex-direction: column; gap: 1.5rem; } .comparison-card { background: #fff; border-radius: 16px; padding: 20px; border: 2px solid #efefef; } .comparison-header { display: flex; justify-content: space-between; font-size: 16px; margin-bottom: 12px; } .comparison-row { display: flex; justify-content: space-between; padding: 8px 0; border-top: 1px solid #efefef; font-size: 14px; color: #1f2937; } .comparison-label { font-size: 14px; width: 30%; } .comparison-value { width: 65%; text-align: right; } @media (max-width: 600px) { .comparison-row { flex-direction: column; align-items: flex-start; } .comparison-value { text-align: left; margin-top: 4px; } } You sent a 15% code only to newsletter subscribers and two days later it has been used 300 times. Many never subscribed: they found the code on a coupon site, or a browser extension dropped it into the cart automatically. They would have bought anyway, and you paid for the discount out of your margin. The basic maths of discounts is in the article on discount codes without losing margin . Here I go deep on leaks: how they happen, which settings stop them and what to do when a code leaks. 1. How a code ends up on coupon sites It is rarely someone stealing the code. Usually it leaves through one of these routes: Subscribers pass it on. The email reaches a friend, then a deals group and from there the sites that collect codes. Influencer codes. They are public by nature, so they reach coupon sites quickly. Coupon affiliates. If the affiliate programme rules don't say which codes they may publish, they publish everything they find. Browser extensions. They automatically try known codes at checkout. A code that worked once reaches every user of the extension. Guessable codes. STORENAME10, BLACKFRIDAY20 or XMAS15 get tried at checkout even if nobody published them. Old codes with no expiry. A forgotten launch code is almost certainly on dozens of sites. Google Merchant Center promotions. A…