How to build a strong discount code
Discount codes look like a small detail, but the gap between a well-crafted one and a rushed one shows up in conversion. Strong codes meet 4 criteria: easy to type, no confusable characters, short enough to remember, and signaling something about the promo when seen in an email or ad.
Three code types and when to use each
- Public code: one for the whole campaign, easy to communicate (e.g. SUMMER20). Best for mass campaigns and email marketing.
- Unique per person: different per recipient or referrer. Best for affiliate, referral and premium campaigns.
- Per channel: different by channel (Instagram, Facebook, podcast). Lets you measure which channel actually converts.
Best practices almost nobody follows
- Avoid ambiguous chars: 0 vs O, 1 vs I vs L. Using them multiplies typos and support tickets.
- Keep length between 6 and 12. Shorter gets guessed, longer gets mistyped.
- Include context when possible: BLACKFRIDAY30, REFERRAL15, PODCAST10. Increases perceived exclusivity.
- Set a clear expiry. Without it, everyone waits to buy later.
- Cap uses per person. Uncapped codes invite abuse.
How to measure if your code campaign worked
Redemption count alone isn't enough. The metrics that matter:
- Use rate: codes redeemed / codes issued. Below 5% means the offer is weak.
- AOV with code vs without: if very different, you may be cannibalizing sales that were going to happen anyway.
- Repeat purchase: did the code user buy again at full price? If not, your program attracts deal hunters, not customers.
- Real margin: discount + free shipping + ops cost. Sometimes "20% off" loses money per unit.
Common mistakes
- Generic codes like "DISCOUNT" or "PROMO" — most likely to leak to coupon aggregator sites.
- Stacking codes without rules (20% off + free shipping with no minimum = guaranteed loss).
- Not communicating rules: minimum spend, exclusions, expiry.
- Reusing the same code monthly. Urgency dies.
- Not briefing support. If agents don't know the rules, customers leave angry.