Yes, this is possible!
The way to do this is by exporting the participants from the old campaign, you just need to click on the "export" button in the campaign dashboard and you will receive a .CSV file, then import them to the new one by using the "Import button" and selecting this .CSV file.
Important: Keep in mind though that the unique referral code will change. This is because the referral code is unique for each campaign and you cannot have the same code in different campaigns.
Tip: What we suggest is that once you import the old participants to the new campaign let them know through an e-mail about your new campaign and also e-mail them their new unique referral link.
If you have turned on the notifications of the campaign they will receive the welcome e-mail of the campaign once you upload them, if you don't wish for them to receive anything, you should turn off notifications of the campaign before uploading them.
Hope this article helped on how to create value from your existing participants. This could work well transitioning from a pre-launch concept to a milestone one.
Get in touch with us if you need further assistance!