A browser add-on that finds and offers discount codes when a shopper reaches a checkout, often earning affiliate commission on the sale.
A coupon extension lives in the shopper's browser. When it recognises a checkout, it offers the codes it holds for that store, and some try them one after another to find the best. Codes reach it from its users, from codes it sees used at checkouts, from brands and networks, and from other listings. Many extensions are publishers on affiliate programmes.
Google's Chrome Web Store has a policy for extensions that earn from affiliate links. Its Affiliate Ads page says an extension must disclose any affiliate programme, may only add affiliate links, codes or cookies when the user gets a direct benefit such as a discount or cashback, and needs a related user action before each one. So when a shopper accepts an extension's offer, it can add its affiliate link to the visit, and under last click the sale can be credited to it.
- Google Search can't find an extension's codes, because they appear inside a checkout.
- If you look at one yourself, use a separate browser profile, and don't accept its offers on your own checkout.
- Your programme terms can say which codes an extension may offer.
The guide to finding where your codes are listed covers extensions and voucher sites side by side.