The document outlines different types of marketing campaigns that can be used at various stages of a buyer's journey and to engage customers. It first describes the three stages a buyer goes through - awareness, consideration, and decision. It then lists 14 types of marketing campaigns, including welcome campaigns for new users, onboarding campaigns to help users understand a new product, repeat purchase campaigns for customer retention, and referral campaigns to encourage existing users to invite friends. The document provides examples of channels like email, push notifications, and SMS that can be used for each campaign type.