Letterby powers growth through waitlists and gamification, but the moment a new subscriber joins is your best chance to engage them, and you only get that moment once. Every second that passes without a reply is a second they could be cooling off or looking elsewhere.

When a new subscriber joins your Letterby list, a Zap can send them an instant SMS welcoming them in, setting expectations, or asking them to complete a step. You can reward them, add them to follow-up sequences, or create a record in Mobile Message. When a new reward is unlocked, send a celebration message so they feel the win immediately and stay invested in your game.

This means your subscribers get a sense of momentum from day one. Fresh signups become engaged followers, rewards feel meaningful because they arrive instantly, and your list stays active because every milestone triggers a real moment of connection.