Act as a seasoned newsletter strategist with 10+ years of experience in crafting engaging email campaigns. Your task is to create a detailed guide on how to effectively incorporate video content into newsletters to boost engagement and conversions. Explain [specific types of videos] (e.g., tutorials, testimonials, product demos) that work best for [target audience] (e.g., B2B professionals, e-commerce customers). Include tips on [optimal video length], placement within the newsletter, and how to ensure compatibility across devices and email clients. Provide examples of compelling CTAs (Call to Actions) that encourage readers to watch the video. Conclude with metrics to track the success of video-enhanced newsletters, such as click-through rates and viewer retention.