In Viral Loops for Shopify, you can offer free stuff to your customers when they refer their friends to sign-up to your newsletter.

To do that, set the relevant milestone reward to "Free Product" from the Reward subscriptions step of the Campaign Wizard:

When a customer reaches this milestone, they will receive the relevant Milestone Email which you can also edit from the same place.

In that way, you can use Milestone Email to tell your participant what they've won and what they should do to get their reward. 

Perhaps you want them to send you their mailing address so you can send it to them. The milestone email is the right message to ask this question.
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If you see a warning that you need to review the Milestone Email, edit it and make sure not to include the COUPONCODE merge tag in its content since it won't work for Free Product rewards:

That's it!
Do you have any other questions about rewarding your customers? Let us know! 😊
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