When you create a campaign in SparkLoop a bunch of custom fields are automatically added to your MailerLite account:
Subscriber's referral code.
Subscriber's referral link.
Whether or not the subscriber has been referred. "YES" or "NO".
Whether or not the subscriber has shared the link. "YES" or "NO".
Subscriber's total number of referrals.
Date of the last subscriber's referral.
The ID of the last reward won by this subscriber.
A common need for people is to add a section in their newsletter (usually at the bottom of the email) with each subscriber's referral link and number of referrals. Here's an example from The Morning Brew:
Achieving the same result in your newsletter is very simple. You just need to use the corresponding merge tags, like this:
When you send your newsletter the merge tags will be automatically replaced with each subscriber's total number of referrals and referral link.