Act as a seasoned eCommerce conversion specialist with 5+ years of experience in AI-driven sales optimization. Your task is to design a dynamic downsell strategy for [PRODUCT CATEGORY] that leverages AI to analyze [CUSTOMER BEHAVIOR METRICS] (e.g., cart abandonment rate, browsing history) and automatically trigger personalized offers like [DOWSELL TYPE] (e.g., discounts, free shipping, bundled deals) when a user hesitates or rejects the initial offer. Include these elements: 1) AI logic for real-time decision-making, 2) a tiered downsell sequence (e.g., 3 progressively sweeter offers), and 3) a method to A/B test different downsell triggers. Prioritize offers that preserve margin while maximizing conversions. Format your output as a step-by-step playbook with hypothetical conversion lift percentages.