You might want to be sure that when you publish a survey via SMS or E-mail campaign that the respondent can only answer the survey once on their device.
Feedbackly recommends that you activate the feature manually for SMS and Email by following these steps:
1. Log in to your Dashboard
2. Click on the Surveys tab on the left hand side of the screen
3. Either select an existing survey from the list or create a new survey, you can read more on creating surveys or using survey templates here
4. Once you have a survey that you wish to launch, click Launch survey and select the touchpoint that you wish to use
5. After choosing the touchpoint tick the box next to Allow only one response per contact
6. Click the next arrow on the bottom right corner of the screen to move forward
7. Move to Launch schedule from the bottom part of the page
8. Here you can choose wether you wish to launch your survey immediately or schedule to launch it later (if you wish to schedule please check out this article)
9. After choosing Launch immediately move to Confirmation and make sure that everything is set up correctly
10. Go to Launch and your survey will be live
How does response limiting actually work?
The system checks if there is "uniqueKey Id" key available in the URL
This key must be special for every single respondent and if the key has already been seen by the system then the survey gets locked after first response
If the respondent has already answered the survey on their device and they try to answer the survey again they will be shown a message that says "thank you for your response! Your response(s) has been saved and cannot be changed anymore"
Please note that for automated campaigns through API (for example through Salesforce) then the duplicates can't be restricted from Feedbackly's side, as the API sends all the collected data per automation.