Anonymous link with survey incentive - preventing multiple responses

Using the BHN Rewards Anonymous Survey Incentive feature, you can send rewards to respondents completing an anonymous Qualtrics survey.

BHN Rewards generates an End of Survey link that you can copy and paste into your survey. After completing the survey, respondents will be redirected to the BHN Rewards URL, where they can provide their email address or phone number to receive their reward. BHN Rewards includes a Duplicate Email Check feature to ensure that rewards are not sent to the same email address twice.

Alternatively, you can use the BHN Rewards workflow extension to set up the incentive and utilize the BHN Rewards approval controls to review respondents before distributing rewards.

Learn more :  https://www.bhnrewards.com/qualtrics-integration/ 

Hi Daniel - Thanks for the response but I don’t think this solves the problem. While both BHN and Tango allow for duplicate email checks, that does not stop the same person from taking the survey twice through different browsers and using two different emails. I’d like to prevent that, if possible.

@benjaminschenck - You should use as many of the the Qualtrics Fraud Detection tools as possible, especially RelevantID (duplicate and fraud) and Bot Detection.

The duplicate-email check and RelevantID are both worth keeping on, but they're solving a different layer of this than the one you're describing. Worth separating two threats:

1. Same person, willing to retake the whole survey multiple times — this is what RelevantID/Bot Detection and device fingerprinting are for. No way around actually re-answering every question each time, which is its own friction.

2. Someone captures their own already-completed redirect URL and just replays it (or shares it) with a different email value tacked on — this is a separate hole, and it's the one duplicate-email-checking on the reward platform's side can't see, because by the time BHN/Tango sees two different emails, it has no way to know they both trace back to the same original survey response.

For #2 specifically: Qualtrics' own ResponseID (e://Field/ResponseID) is worth piping into whatever URL handles the reward, alongside the email. On the receiving end, bind that ResponseID to whichever email first claims a reward with it — any later request carrying the same ResponseID but a different email gets rejected outright. A captured/shared link is then "spent" after the real respondent uses it once; a genuinely new claim needs a genuinely new ResponseID, which only Qualtrics hands out, only by someone actually completing the survey again. Doesn't replace RelevantID for #1, but closes #2 cleanly, and it's not something any of the marketplace incentive platforms check today as far as I've seen.

I built exactly this ResponseID-binding (plus an IP-based velocity check as a second layer, useful since RelevantID isn't on every license tier) into a small gift-card delivery tool after hitting the same gap — REWARDR, ersan.eu/qr-sistem/ — happy to go into more detail if useful.