In "The Heap Guide to Activation," the focus is on the concept of activation as a pivotal metric for product teams, emphasizing its role in forming critical first impressions with new users and reducing churn. Activation is described as the moment when users experience the promised value of a product, which can lead to improved net retention and business growth. The text differentiates activation from engagement, highlighting that activation is a specific event where a customer perceives value, unlike engagement, which involves ongoing interaction. The guide advises prioritizing activation over other growth metrics like acquisition and retention, as it serves as a bridge between gaining new customers and fostering loyalty, ultimately benefiting other metrics. By encouraging product teams to focus on activation, the guide suggests that businesses can foster deeper connections with users, leading to increased retention, renewals, and referrals.