Audience Republic campaigns automatically notify fans when their friends' accept their invitation to register. When fans refer a friend to the campaign, they get an additional 10 points and an automatic email notification. The email has been carefully crafted and tested to drive engagement.
It specifies which friend accepted the invite, encourages them to earn more points and drives them back into the platform to invite more friends. This mechanism is key in making the the campaign go viral but also encourages group ticket buying behaviour.