The document discusses 5 tactics for increasing customer engagement through cross-channel marketing: 1) enhance follow-up emails by using multiple channels like push notifications and in-app messages, 2) provide personalized content to exceed customer expectations, 3) set up triggered push notifications to deliver real-time value, 4) use retargeting ads as they are more effective on past visitors, and 5) always perform A/B testing and optimization. The goal is to give customers choice in how they engage with brands across different channels. Increasing customer engagement through these tactics can help businesses perform better.