Improving email placement in Gmail's Primary tab is a complex process involving a multi-faceted approach. It starts with establishing a strong sender reputation through practices like warming up your IP address, maintaining a clean and segmented email list, and avoiding purchased lists. Proper email authentication using SPF, DKIM, and DMARC is essential for verifying your identity and preventing spoofing. Creating engaging and personalized content, avoiding spam triggers, and optimizing email frequency are vital for encouraging subscriber interaction. Technical aspects include using a consistent sending IP, adhering to email content and formatting best practices, providing clear unsubscribe options, and monitoring your sender reputation using tools like Google Postmaster Tools. It is also important to build relationships with your subscribers by sending valuable content and encouraging engagement. External factors, like list bombing, need to be understood and addressed. Overall, avoiding tactics that attempt to 'outwit' Gmail’s algorithms and instead focusing on providing a quality, authenticated, and engaging experience for subscribers is key.