Turning Readers Into Referrers

Referral programs get pitched as a growth hack, install this widget, offer subscribers a reward for bringing friends, watch the list grow itself. I've tried versions of this, and the honest result is that formal referral programs are mostly overhead for a newsletter under a few thousand subscribers, and genuinely useful only once you have enough volume for the math to work. Before you build a program, it's worth understanding why people actually forward a newsletter issue in the first place, because that behavior is available to you at any list size, with no software required.