When you create a campaign in SparkLoop a bunch of custom fields are automatically added to your MailerLite account:
RH_SUBID Subscriber's ID.
RH_CODE Subscriber's referral code.
RH_REFLINK Subscriber's referral link.
RH_ISREF Whether or not the subscriber has been referred. "YES" or "NO".
RH_ISSHARER Whether or not the subscriber has shared the link. "YES" or "NO".
RH_TOTREF Subscriber's total number of referrals.
RH_LASTREF Date of the last subscriber's referral.
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.