DupeGuard

DupeGuard stops customers from exploiting your discounts — it doesn't manage the discounts you create.Install it and it scans your recent orders for free, then shows a dollar figure: how much of your one-time discount went to the same shopper under a different email.It looks past the email address — Gmail aliases, disposable inboxes, repeat phone numbers — and links accounts that are one person. Every flag comes with a plain-language reason. Monitor, flag, or block: you choose.