How Promo Codes Actually Work — and How to Spot a Dead One

Most coupon pages are built by scraping. A bot collects every promo code that has ever circulated for a store, pastes the full list onto a page, and marks the top one "verified" whether or not anyone has typed it into a checkout this year. That's why the first promo code on a lot of sites has been dead for months — and why understanding how promo codes actually work changes what you should expect from WorthCodes and every other coupon site you visit.

Where every promo code comes from

Merchants create codes in two ways:

• Public campaign codes — WINNING-style promo codes printed in newsletters, launch posts and affiliate partners' pages. They work for everyone, until the merchant expires them.
• Unique codes — one-per-customer codes from loyalty programs or abandoned-cart emails. They only work for the account they were issued to, so a scraper that copies one makes a promo code that looks real and never works for anyone else.

Both look identical on a coupon site. That's the core problem: a page can't tell you which kind of promo code it's listing unless someone actually ran it through a checkout.

Why so many listed promo codes are dead

Affiliate-driven coupon sites make money when you click through and buy. The incentive is traffic, not accuracy — a page of 40 promo codes where 35 are expired still gets the click. Re-verification costs money; scraping costs nothing. So the industry default is to list everything and let the shopper do the testing.

We think that's backwards. On WorthCodes a promo code only appears after it survives a real checkout, and it gets marked dead the day it fails. A live example: the TrendTrack promo code page shows one verified code, the evidence log behind it, and nothing else.

The 30-second check before you paste any promo code

1. Check the date it was "verified". If a page claims a promo code was tested, look for an actual date, not "verified today" rendered fresh on every visit. Static claims that update themselves are a red flag.
2. Count the codes. A page listing 40 promo codes with no dates is a scraped dump. A page listing 1–3 codes with evidence is curated.
3. Read the terms, not the headline. "20% off" means nothing until you know whether the promo code applies to your plan, your region and new vs existing accounts. Real pages state eligibility; dumps don't.
4. Confirm the total before paying. The discount field is right before payment for a reason. If the total doesn't move, the promo code is dead — no matter what the badge said.

If the promo code is dead: what actually saves money

If the code works, you're done. If it's dead, the merchant's own pricing page is often the better deal — annual billing usually beats a lapsed promo code. And if you're ever unsure whether a subscription discount is legit, the FTC's consumer guidance on subscriptions, free trials and auto-renewal is the best neutral reference on what merchants can and can't do with recurring billing.

For a worked example of all of this — per-tier math, stacking rules, the works — read our TrendTrack discount code guide, the first post in the WorthCodes blog series.